A theoretical study of large planar [N]phenylenes.

Ab initio studies of 14 [N]phenylenes containing 12-membered rings furnish geometries, energies, standard heats of formation, NICS(1) values, and proton chemical shifts. The extent of double-bond localization, DeltaR (in A), for each type of the 58 unique six-membered rings-angular, branched, and terminal-varies linearly with both their NICS(1) values and proton resonances. Values of these parameters depend upon the number and type of neighboring rings.

Properties of phenylene-based hydrocarbon bowls and archimedene.

Geometries, energies and magnetic shieldings are reported at the ab initio B3LYP/6-31G* level for the phenylene cluster C120 (archimedene) and eight phenylene-based hydrocarbon bowls consisting of four-, six-, and ten-membered rings. The six-membered rings are branched, angular, or terminal. The latter are the most aromatic, based upon NICS criteria and lack of substantial bond alternation.

[How does eczema arise?].

New experimental results on the role of T cells and keratinocytes have led to a better understanding of eczematous inflammation and can help explain both the clinical and histological pictures of eczema. Besides activated endothelial cells and adhesion molecules, a complex interaction of numerous chemokines controls the recruitment of T cells from the blood vessels and their migration into the dermis and epidermis. Activated T cells damage the epidermis by pro-inflammatory cytokines and can induce apoptosis of individual keratinocytes through "killer molecules".

IgE-mediated and T cell-mediated autoimmunity against manganese superoxide dismutase in atopic dermatitis.

Background: Autoreactivity of patients with atopic dermatitis (AD) to human proteins has been postulated as a decisive pathogenetic factor for AD.

Objective: In this study, it was investigated whether the stress-inducible enzyme manganese superoxide dismutase (MnSOD) of human and fungal origin might act as an autoallergen in atopic dermatitis.

Methods: Patients with AD (n = 69; mean SCORAD [SCORing Atopic Dermatitis], 27) and other inflammatory skin diseases as well as with inhalant allergies were investigated.

Different natural killer (NK) receptor expression and immunoglobulin E (IgE) regulation by NK1 and NK2 cells.

Many studies concerning the role of T cells and cytokines in allergy have been performed, but little is known about the role of natural killer (NK) cells. Accordingly, the expression of co-stimulatory, inhibitory and apoptosis receptors, cytokine profiles and their effect on immunoglobulin isotypes were investigated in polyallergic atopic dermatitis (AD) patients with hyper immunoglobulin E (IgE) and healthy individuals. AD patients showed significantly decreased peripheral blood NK cells compared to healthy individuals.