Search results for "Delayed hypersensitivity"
showing 5 items of 15 documents
Delayed-type skin reactions in bursectomized or thymectomized chickens.
1977
Chickens can easily be induced to develop delayed-type skin reactions to oxazolone when animals are sensitized 7 days before the challenge. The reaction is quantitated by assessing the increase in wattle thickness: maximum reactions occur 24 h after challenge. The reaction is inhibited by neonatal thymectomy or bursectomy; these findings therefore suggest also an important B-derived component in delayed hypersensitivity to oxazolone.
Demethylnobiletin inhibits delayed-type hypersensitivity reactions, human lymphocyte proliferation and cytokine production
2007
Background and purpose: Our aim was to examine the effect of demethylnobiletin on various experimental models of delayed-type hypersensitivity (DTH) reactions and to determine its influence on the mediators and enzymes involved in these reactions. Experimental approach: DTH was induced in mice by oxazolone, dinitrofluorobenzene (DNFB) and sheep red blood cells (SRBC). The effect of demethylnobiletin on the ensuing DTH was studied, especially in relation to oedema formation, cell infiltration and tissue damage. Its activity on different mediators implicated in DTH reactions was also determined and its effect on nitric oxide synthase (NOS)-2 analysed. Finally, its influence on T lymphocyte pr…
Pharmacological approach to the pro- and anti-inflammatory effects of Ranunculus sceleratus L.
2003
Ranunculus sceleratus is a widespread species with unique toxicological and pharmacological activities. The present study seeks to assess this species' ability, both in vitro and in vivo, to modulate processes involved in inflammations. To this end, different extracts from the aerial parts of the plant were tested in several models of acute inflammation induced by tetradecanoylphorbol acetate (TPA), arachidonic acid (AA), and carrageenan, as well as in two models of delayed hypersensitivity induced by oxazolone and dinitrofluorobencene (DNFB). The extracts were also assayed in models of eicosanoid and elastase release by intact cells. When tested in vivo, all of the extracts showed anti-inf…
Role of IL-4 in delayed type hypersensitivity
1996
SUMMARY IL-4 plays a key role in the contact sensitivity skin reaction. This has several implications. First, the view that contact sensitivity (CS) is only mediated by cells with a Th1 profile of cytokine secretion needs modification, in the light of the essential role of IL-4 at the effector stage. Second, the concept of a single cell involved in the systemic transfer of CS is no longer tenable, as it is known that both αβ and γδ cells are required. Studies with the cell lines (which contain both αβ and a few γδ cells) suggest that this double requirement may involve the action of IL-4 on γδ cells, which bear receptors for IL-4. Finally, the view that T cell lines only transfer CS when in…
Allergic Contact Dermatitis to Benzocaine: The Importance of Concomitant Positive Patch Test Results
2013
Local anesthetics are widely used in clinical practice, and adverse effects are not uncommon. Delayed hypersensitivity reactions are among the most common effects, but immediate-type reactions may also occur. Patch testing should be considered in patients with hypersensitivity reactions. We present a case of allergic contact dermatitis to benzocaine that was detected incidentally by patch testing and highlight the importance of correctly interpreting patch test results when there are concomitant positive reactions.