[Acute myocardial infarction following a wasp sting in a patient with normal coronary vessels]. / Akut myokardieinfarkt efter hvepsestik hos en patient med normale koronarkar.

A case of a myocardial infarction after a wasp sting in a 39-year old man is reported. Subsequent coronary angiography was normal. Spasm in the coronary arteries and thrombocyte aggregation secondary to anaphylaxis may be the underlying factors.

T cell responses affected by aminopeptidase N (CD13)-mediated trimming of major histocompatibility complex class II-bound peptides.

Endocytosed protein antigens are believed to be fragmented in what appears to be a balance between proteolysis and MHC-mediated epitope protection, and the resulting peptide-MHC complexes are transported to the surface of the antigen-presenting cells (APC) and presented to T cells. The events that lead to antigenic peptide generation and the compartments where antigen processing takes place remains somewhat enigmatic. The importance of intracellular antigen processing has been well established; however, it is unclear whether additional processing occurs at the APC surface. To follow antigen processing, we have identified a pair of T cell hybridomas that recognize a long vs. a short version of the same epitope. We have used prefixed APC and various protease inhibitors to demonstrate that the APC surface has a considerable potential for antigen processing. Specific antibodies further identified the exopeptidase Aminopeptidase N (APN, CD13) as one of the enzymes involved in the observed cell-surface antigen processing. The NH2-terminal end of the longer peptide could, even while bound to major histocompatibility complex (MHC) class II molecules, be digested by APN with dramatic consequences for T cell antigen recognition. This could be demonstrated both in cell-free systems using purified reagents and in cellular systems. Thus, MHC class II and APN may act in concert to generate the final T cell epitopes.

[Tobacco and leukocytosis]. / Tobak og leukocytose.

Six heavy smokers with leucocytosis are described. Except for leucocytosis, laboratory tests were normal. A strong tobacco-induced leucocyte response indicates an increased risk of developing arterial diseases and lung diseases.