We report 2 cases of Haemophilus parainfluenzae endocarditis and review 34 cases of HACEK endocarditis from the literature. HACEK organisms are the most common cause of Gram-negative endocarditis in children. They have a propensity to form friable vegetations (especially H. parainfluenzae) that break off and cause symptomatic emboli. HACEK endocarditis (from a review of the 36 published cases) may involve previously normal hearts (33%), may be complicated by embolization (31%) and may require vegetectomy or other surgery (31%). Mortality with HACEK endocarditis was 14%. HACEK organisms may be resistant to penicillins but are susceptible to third generation cephalosporins.

This paper describes the synthesis, characterization, and photochemical behavior of a new light-activated material for the photoimmobilization of antigens. The material is a derivative of cross-linked polyacrylamide that incorporates photoactive o-nitrobenzyl carbamates. When irradiated, the polymer undergoes a photochemical rearrangement to produce primary amines that can be used as molecular attachment sites. We monitored the photoconversion of thin (1-2 µm) polymer films that were deposited on silicon wafers or fused silica substrates using FT IR spectroscopy and UV-vis spectroscopy. To produce patterned polymer-modified substrates, we irradiated the material using a photolithographic mask. This process yielded 10-µm lines of photogenerated amines, to which an amine-reactive antigen (2,4,6-trintrobenzenesulfonic acid) was covalently bound. When we used this antigen-patterned substrate in a competitive fluorescence immunoassay containing tetramethylrhodamine-labeled anti-2,4-dinitrophenyl antibodies and 2,4-dinitrophenol, concentrations of 2,4-dinitrophenol as low as 2.3 µg/mL were detectable.