Search results for " contact"

Update of immune events in the murine contact hypersensitivity model: toward the understanding of allergic contact dermatitis.

2013

Allergic contact dermatitis (ACD) is one of the most common skin diseases, consisting of sensitization and elicitation phases. With the advancement of technology and the discovery of new types of immune cells, our knowledge of the immunological mechanisms of contact hypersensitivity (CHS) as a murine model of ACD has expanded significantly in the past decade. For example, by introducing regulatory T cells, CD4(+) T-helper 17 cells, and Langerin-positive dermal dendritic cells, the initiation and termination mechanism of CHS has been revealed. In addition, the role of mast cells in CHS, long a matter of debate, has become apparent by developing conditional mast cell-deficient mice. Moreover,…

A Cohesive-Frictional Interface Model with Frictional Properties Degradation

2009

The paper is devoted to an interface constitutive modeling which couples a cohesive behavior, based on the damage mechanics theory, with a frictional one, defined in a non-associative plasticity framework. By means of a specific interpretation of the damage variable, the formulation follows the transition of the initial sound interface material layer, up to the fully cracked condition. The macrocrack surfaces have initial frictional properties and is subjected to degradation phenomena. Namely, the smoothing and breaking of surface asperities cause a progressive reduction of dilatancy effects and also of the frictional angle. These phenomena are modeled as uncoupled: dilatancy saturation is …

Prevention and reversal of superantigen-induced anergy by contact allergen exposure

1995

The superantigen Staphylococcal enterotoxin B (SEB) and the contact allergen 2,4-dinitrofluorbenzene (DNFB) both react with V beta 8+ T-cells delivering distinct signals. Pre-treatment with DNFB painted onto the same skin site where SEB was to be injected, prevented the induction of anergy in V beta + T-cells that was otherwise induced after SEB had been injected intradermally over a period of 2 weeks. Application of the irritant sodium dodecyl sulfate (SDS) instead of DNFB did not exert this effect. Application of DNFB at a site distant from the site where SEB was injected resulted in a much weaker inhibitory influence on the induction of anergy by SEB. Established anergy of V beta 8+ T-ce…

Comparative studies of ferric green rust and ferrihydrite coated sand: Role of synthesis routes

2008

International audience; A comparative study of ferrihydrite and ferric green rust coated sand prepared by three synthesis routes has been outlined in the present contribution. The two minerals displayed inverse properties in terms of quantity of deposited iron for all three methods investigated. For ferric green rust coating, a newly proposed synthesis route named as dry contact method was efficient for the maximum quantity of iron with almost full coverage area. Considering the similar parameters, the modified wet synthesis method designated as reactive method provides the optimum results for ferrihydrite coated sand. These coatings have been characterised by different surface analysis tec…

A Particular Case of suicide Committed With a Double-Barreled Shotgun

2008

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 …

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…