1,721,025 research outputs found
Analisi morfologica degli effetti di radiazioni ionizzanti su epidermide umana in un modello anatomico di colture organotipiche
No full textSkin is a target organ for crucial side-effects of radiotherapy and the early effects on epidermis remain to be fully elucidated. Organotypic cultures of human skin can help in defining the early effects difficult to study in humans. To characterize our model, we performed a keratinocyte proliferation analysis in a time course study and then in irradiated samples. We evaluated the effects on terminal differentiation, intercellular adhesion and apoptosis by immunofluorescence and ultrastructural analysis. Bioptic fragments (n=8) were obtained from cosmetic surgery of young healthy women, cultured in Transwell, and harvested 24 or 48 hours after exposure to a single 2 Gy dose of gamma-rays. Epidermal proliferation progressively decreased in the time course study and significantly inhibited 24 hrs after gamma-rays. Patterns of CK10, INV, Dsg1 and Dsc1 proteins distribution were comparable in all samples. P53 was similarly detected in scattered positive keratinocytes in the spinous layer of 24 hrs samples, whilst in 48 hrs irradiated samples was expressed starting from basal layer. TEM analysis indicated that no desmosomal ultrastructural modifications occurred. In 24hrs irradiated skin the basal layer was undamaged but a condensation of intermediate filaments and apoptosis were evident in the upper spinous layers. In 48hrs irradiated skin apoptotic nuclei started from the basal layer. The epidermal homeostasis is rapidly altered by a single clinical dose of gamma-rays
Organotypic cultures of human keratinized oral mucosa : an anatomical model for studying the early effects of oral cancer radiotherapy
No full textBurning mouth syndrome possibly linked with an amalgam tattoo : clinical and ultrastructural evidence
No full textMorphological features of epidermal proliferation and differentiation in normal human breast skin organotypic cultures : a time course study
No full textMorphological analysis of gamma rays effects in organotypic cultures of human breast skin
No full textSmall diameter porous honeycomb substrates are more effective at cultivating human keratinocyte and dermal fibroblast cultures
No full textUnsupported keratinocyte grafts, while fragile, provide excellent clinical benefits and wound coverage. We aim to overcome the fragile nature of these grafts by using keratinocytes and fibroblast grafts grown on biocompatible, biodegradable, hexagonalpacked porous poly-calprolactone membranes. To confirm the feasibility of this proposal, human epidermal keratinocytes and dermal fibroblasts were cultured on membranes with controlled-sized pores (ranging from 3–20 microns). We examined the effects of growing monocultures on these porous membranes and on flat (pore less) polymer films. Cell adhesion, growth and migration rates and basic morphology were examined using confocal laser scanning microscopy. Cell ultrastructure was subsequently examined using scanning and transmission electron microscopy. Human keratinocytes and fibroblasts attached to all porous membranes. Furthermore, small pore (3 and 5 micron) membranes provided the best surfaces, on which fibroblasts could attach, adhere, divide and grow. However, keratinocytes, the most discerning of the two cell types adhered and grew best on 3 micron pore membranes. In addition, cells were prevented from undergoing transmembrane migration (to the opposing membrane surface) by the 3 micron porous membrane. Larger pores (45microns) allowed migration of both fibroblasts (and to a lesser extent keratinocytes) on to the opposite side of the membrane. Our data show that keratinocytes and fibroblasts attached and grew optimally on small pore membranes due to greater pores numbers and a larger surface area over which cells adhere. The small pore size also inhibits cells from traversing the membrane while, at the same time allowing cell adhesion, matrix communication and diffusion of soluble nutrients/factors from the environment. These characteristics are important in development of graft technology, in the treatment of human skin wounds and in the study of cell-substrate adhesion on novel patterned structure
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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