Phenotype of asthmatics with increased airway S-nitrosoglutathione reductase activity.

S-Nitrosoglutathione is an endogenous airway smooth muscle relaxant. Increased airway S-nitrosoglutathione breakdown occurs in some asthma patients. We asked whether patients with increased airway catabolism of this molecule had clinical features that distinguished them from other asthma patients. We measured S-nitrosoglutathione reductase expression and activity in bronchoscopy samples taken from 66 subjects in the Severe Asthma Research Program. We also analysed phenotype and genotype data taken from the program as a whole. Airway S-nitrosoglutathione reductase activity was increased in asthma patients (p=0.032). However, only a subpopulation was affected and this subpopulation was not defined by a "severe asthma" diagnosis. Subjects with increased activity were younger, had higher IgE and an earlier onset of symptoms. Consistent with a link between S-nitrosoglutathione biochemistry and atopy: 1) interleukin 13 increased S-nitrosoglutathione reductase expression and 2) subjects with an S-nitrosoglutathione reductase single nucleotide polymorphism previously associated with asthma had higher IgE than those without this single nucleotide polymorphism. Expression was higher in airway epithelium than in smooth muscle and was increased in regions of the asthmatic lung with decreased airflow. An early-onset, allergic phenotype characterises the asthma population with increased S-nitrosoglutathione reductase activity.

Functionalized nanocrystal-tagged fluorescent polymer beads: synthesis, physicochemical characterization, and immunolabeling application.

A methodology for incorporating solubilized CdSe/ZnS core/shell nanocrystals (NCs) into functionalized carboxylated polystyrene latexes 0.3-1 microm in diameter via a swelling procedure was developed and used for the production of homogeneous, highly fluorescent polymeric beads (HFPBs), which were found to be comparable in brightness to standard polymeric microspheres doped with organic fluorophores and more photostable than the latter by more than 50 times (Fluoresbrite yellow-orange microspheres were used as an example). The three-dimensional (3D) confocal analysis of individual 1-microm HFPB demonstrated that the beads were doped with the NCs almost homogeneously. HFPBs 0.3 microm in diameter were conjugated with anti-mouse polyvalent immunoglobulins and used for immunofluorescent detection of p-glycoprotein, a mediator of the multidrug resistance phenotype, overexpressed in the membrane of MCF7r breast adenocarcinoma cells. The photostability of NCs-tagged HFPBs offers obvious advantages for the reconstruction of 3D confocal fluorescence images of antigen distribution, and their exceptionally high brightness combined with photostability permits the detection of a single antigen molecule using a standard epifluorescence microscope.