Search results for "CONTACT"
showing 10 items of 1003 documents
Enhanced expression of IL-8 in normal human keratinocytes and human keratinocyte cell line HaCaT in vitro after stimulation with contact sensitizers,…
1994
Abstract To investigate the interleukin-8 production of keratinocytes after stimulation in vitro we have used various agents: (i) contact sensi-tizer (2,4-dinitrofiuorobenzene, 3-n-penladecylcatechol); (ii) tolerogen (5-methyl-3-n-pentadecylcatechol); (iii) irritant (sodium lauryl sulfate). Interleukin-8 gene expression was assessed by northern blot hybridization of the total cytoplasmic RNA extracted from subconfluent normal human keratinocyte cultures and the keratinocyte cell line HaCaT using a radiolabeled DNA probe specific for human interleukin-8. Intcrleukin-8 gene expression was markedly increased upon in vitro stimulation after 1-6 h with contact sensitizers, tolerogen and the irri…
Cannabinoid 1 Receptors in Keratinocytes Modulate Proinflammatory Chemokine Secretion and Attenuate Contact Allergic Inflammation
2013
Abstract Epidermal keratinocytes (KCs) and cannabinoid (CB) receptors both participate in the regulation of inflammatory responses in a mouse model for allergic contact dermatitis, the contact hypersensitivity (CHS) response to the obligate sensitizer 2,4-dinitrofluorobenzene. In this study, we investigated the cellular and molecular mechanisms how CB1 receptors attenuate CHS responses to 2,4-dinitrofluorobenzene. We used a conditional gene-targeting approach to identify the relative contribution of CB1 receptors on epidermal KCs for the control of CHS responses. To determine the underlying cellular and molecular mechanisms that regulate inflammatory responses in the effector phase of CHS, …
Cellular and molecular mechanisms in the induction phase of contact sensitivity.
1995
During the induction phase of contact sensitivity, hapten-specific Th1 cells are primed by epidermal Langerhans cells. These Langerhans cells present hapten on MHC class II molecules and provide costimulatory signals. This presentation discusses the induction of cytokines in Langerhans cells and keratinocytes by haptens and their regulatory effects on contact sensitivity. Haptens were painted on the skin of normal BALB/c mice and epidermal cells were prepared at various times thereafter. Langerhans cell-derived interleukin (IL)-1 beta mRNA was observed as early as 15 min after hapten paining. In keratinocytes, tumor necrosis factor-alpha, IL-1 alpha, IP-10, MIP-2 and IL-10 were found to be …
Rottlerin induces a transformed phenotype in human keratinocytes.
2001
PKCdelta plays a fundamental role in cell cycle control. Consistent with its proposed tumour suppressor function, ras transfection of the human keratinocyte cell line HaCaT results in a loss of PKCdelta expression mediated by TGFalpha (Exp. Cell Res., 219, 299, 1995). To get more insight into the role of PKCdelta in keratinocytes, we investigated the effects of Rottlerin, a specific inhibitor of protein kinase Cdelta, in HaCaT cells. After Rottlerin treatment, HaCaT cells lost their cobble-stone morphology and displayed a spindle-shaped, fibroblastic phenotype. Additionally, the establishment of cell-cell contacts was prevented. This was caused by an internalization of E-cadherin and beta-c…
Induction of inflammatory cytokines in murine keratinocytes upon in vivo stimulation with contact sensitizers and tolerizing analogues
1992
In order to elucidate the role of keratinocytes (KCs) in the induction of contact sensitivity, we applied various contact sensitizers [2,4-dinitrofluorobenzene (DNFB), urushiol, 3-n-pentadecylcatechol (PDC), 4-ethoxymethylene-2-phenyloxazol-5-one (oxazolone)] and tolerizing compounds [2,4-dinitrothiocyanobenzene (DNTB), 5-methyl-3-n-pentadecyl-catechol (5-Me-PDC)] onto the earskin of non-sensitized Balb/c mice. In addition, we applied croton oil as a non-sensitizing, but stimulatory agent. Cytokine production was demonstrated by Northern blot hybridization of the total cellular RNA extracted from epidermal cells depleted by Langerhans cells and Thy 1+ dendritic cells using radiolabeled DNA …
Nonsurgical Procedures for Keratoconus Management
2017
Objectives. To describe the past 20 years’ correction modalities for keratoconus and their visual outcomes and possible complications.Methods. A review of the published literature related to the visual outcomes and possible complications in the context of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was performed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed.Results. The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and soft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens sy…
Visual quality with corneo-scleral contact lenses for keratoconus management
2018
Purpose: To assess the visual quality achieved by fitting corneo-scleral contact lenses (CScL) for keratoconus management. Methods: Thirty patients with keratoconus presented to have CScL fitted because of the unsatisfactory visual quality they experienced with their contact lenses or spectacles. The eye examination included visual acuity assessment, anterior eye biomicroscopy, ocular fundus examination, corneal topographic analysis, endothelialcell count, contrast sensitivity and aberrometry. The fitting process was performed using a diagnostic trial set. Subjective visual quality and comfort, and contact lens wear time were also reported. Patients were monitored for one year. Results: Thr…
BIO Bragg gratings on microfibers for label-free biosensing
2021
[EN] Discovering nanoscale phenomena to sense biorecognition events introduces new perspectives to exploit nano science and nanotechnology for bioanalytical purposes. Here we present Bio Bragg Gratings (BBGs), a novel biosensing approach that consists of diffractive structures of protein bioreceptors patterned on the surface of optical waveguides, and tailored to transduce the magnitude of biorecognition assays into the intensity of single peaks in the reflection spectrum. This work addresses the design, fabrication, and optimization of this system by both theoretical and experimental studies to explore the fundamental physicochemical parameters involved. Functional biomolecular gratings ar…
Contact sensitivity as a model for T-cell activation in skin.
1995
Contact sensitivity has served as a useful model for the primary activation of T cells in skin and skin-associated lymphoid tissue. We have been interested in the early signals necessary for the induction of an allergen-specific T-cell response, as well as the factors controlling the intensity and extent of such an immune reaction. Because cytokines qualified as possible candidate molecules involved in directing primary immune responses in skin, we studied the early changes in the cytokine pattern of the epidermis. Apart from defining a cytokine pattern specifically induced only after application of allergen, we also identified Langerhans-cell-derived interleukin (IL)-1β as the first cytoki…
Molecular adhesion interactions between Langmuir monolayers and solid substrates
1998
Abstract Substrate-monolayer adhesion interactions between differently prepared SiO2 surfaces and Langmuir monolayers were investigated. From the relation between the contact angle and the surface tension of a Langmuir monolayer in the configuration of Langmuir wetting the work of adhesion between the substrate and the monolayer as a function of the molecular packing and the transfer ratios was determined. Thus the molecular work of adhesion of different SiO2-dimyristoylphosphatidylethanolamine surfaces was quantified. The relation between the local adhesion interactions and the molecular packing and structure is presented and substrate-induced phase transitions are discussed.