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Food proteins may be modified during processing and storage through reactions with reducing sugars (Maillard reaction, glycation) or by reactive oxygen species (protein oxidation). Little is known about particular reactions at the interface of glycation and oxidation. In the present study, the glycated amino acid pyrraline (6-(2-formyl-5-hydroxymethyl-1-pyrrolyl)-l-norleucine) and the proteinogenic amino acids tyrosine and tryptophan were subjected to different types of oxidation. The stability of the amino acids was assessed by HPLC with UV detection, whereas oxidation products were assigned by HPLC with triple quadrupole or time-of-flight mass spectrometric detection. Conditions that lead to oxidation of aromatic proteinogenic amino acids can also lead to oxidation of pyrraline. Pyrraline was particularly unstable in the presence of permanganate, hypochlorite, and under hydroxyl radical-generating conditions (iron, ethylenediaminetetraacetic acid, ascorbic acid). Evidence obtained by high-resolution mass spectrometry revealed the oxidation of pyrraline to 6-(2,5-diformyl-1-pyrrolyl)-l-norleucine, 6-(2-carboxy-5-hydroxymethyl-1-pyrrolyl)-l-norleucine, 6-(2-formyl-5-carboxy-1-pyrrolyl)-l-norleucine, and 6-(2,5-dicarboxy-1-pyrrolyl)-l-norleucine in the presence of potassium permanganate. The latter product was isolated by semipreparative HPLC and characterized by NMR. Under hydroxyl radical-generating conditions, pyrraline is hydroxylated at the ring under formation of 6-(2-formyl-4-hydroxy-5-hydroxymethyl-1-pyrrolyl)-l-norleucine or 6-(2-formyl-3-hydroxy-5-hydroxymethyl-1-pyrrolyl)-l-norleucine. This study shows that the so-called "advanced glycation end products" are no end products of the Maillard reaction, but may undergo further chemical degradation reactions.

Focuses on the treatment of psoriasis with a source of artificial ultraviolet radiation (UVR) using a carbon arc lamp. Additional of metal halides to mercury lamps to improve the emission in certain regions of the ultraviolet and visible spectra; Examination of the therapeutic effect of lamps; Erythemal response of human skin to UVR.

The side effect of phototherapy with 8-methoxypsoralen was divided in short- and long-term damage. From 1969 until 1980 2,013 patients were treated. The pattern of alteration by PUVA depends on doses, continuance of therapy, and type of dermatoses. The spontaneous development of tumors, the initiating or promotion of tumors by PUVA, as well as a regression of tumors by PUVA has to be taken into account regarding the absolute numbers of tumors after PUVA therapy. The risk of the PUVA therapy depends on the doses and continuance of the treatment including the combination with other sources of radiations or natural sun-exposition. The possibilities lower the total doses of light energy by drug combinations are discussed according the recommendation of several teams in Germany. The quality of the remaining years of a patient's life is the limiting factor in deciding whether a risk is involved in photochemotherapy. The risk only involved the skin. The stress of chemotherappy on patients with additional pathologic conditions can be controlled. [ABSTRACT FROM AUTHOR]

Explores the association of dermatitis herpetiformis to the gut. Presence of immunoglobulin (IgA) deposits in the upper dermis of the uninvolved skin; Remission of both the skin and intestinal lesions; Acquisition of secretory component from the gut epithelium by IgA molecules.