Imaging of reactive oxygen species generated in vivo.

Purpose: We sought to image the biodistribution of reactive oxygen species (ROS) within the living body using an in vivo electron spin resonance (ESR) imaging system using a spin probe, 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrroline (ACP) that produces ESR-detectable nitroxide upon reaction with ROS.

Methods: Acute hepatic injury was induced in mice by priming with heat-killed Corynebacterium parvum followed by injection of a low dose of lipopolysaccharide. ACP was administered intravenously and an in vivo ESR imaging system was used to visualize hepatic oxidative stress.

What can be revealed by extending the sensitivity of HBsAg detection to below the present limit?

Background/aims: We investigated what can be revealed by extending the sensitivity of HBsAg detection to below the present limit.

Methods: We examined the sensitivity of this immunoassay in comparison with real-time PCR detection of HBV DNA using serially diluted sera from HBV carriers. Low HBsAg was measured in 210 healthy volunteers and 368 patients with non-B chronic liver diseases who were negative for HBsAg by a standard EIA method.

Relationship between airborne Cry j 1 and the onset time of the symptoms of Japanese cedar pollinosis patients.

Background: Some patients with Japanese cedar (JC) pollinosis already show pollinosis symptoms before the first day of the pollen season as determined by microscopic pollen counts.

Methods: Airborne pollen allergen (Cry j 1) levels were measured by electron spin resonance radical immunoassay, a highly-sensitive method for Cry j 1 with a sensitivity 10-100-fold higher than conventional enzyme-linked immunosorbent assay. The symptom data from patients with JC pollinosis were collected from a mobile phone site, "pollen check sheet", and the onset times of the patients' symptoms were analyzed.

In vivo detection of intrinsic reactive oxygen species using acyl-protected hydroxylamine in puromycin nephrosis.

Intrinsic reactive oxygen species (ROS) in a rat model of human minimal change nephropathy were detected directly using an in vivo electron paramagnetic resonance (EPR) method with 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine (ACP) in real time. The nephrosis was induced by the intravenous administration of 75 mg/kg of puromycin aminonucleoside (PAN). It was found that ROS in the kidney were increased 1 h after the administration of PAN.

[Development of the simple method for measurement the content of Cry j 1 in the air by latex agglutination test].

Background: In order to develop an easy method for measure the airborne C. japonica pollen allergen (Cry j 1) without any utensils or a special apparatus, we examined latex agglutination test for the purpose.

Methods: The latex beads were reacted with the anti-Cry j 1 polyclonal antibody, and the beads were blocked with bovine serum albumin (sensitized beads).

[Development of super-sensitive radical immunoassay for Cry j 1].

We have been developed super-sensitive method of Cry j 1 measurement by ESR radical immunoassay using p-acetamidophenol and hydroxylamine system. The detection limit for Cry j 1 was 3.5 pg/ml.

Synthesis and enzyme-catalyzed hydrolysis of a radical-masked glycosylated spin-label reagent.

N1-Acetoxy-2,2,6,6-tetramethylpiperidin-4-yl 2,3,4,6-tetra-O-benzyl-alpha- and -beta-D-glucopyranosides (3-alpha, beta) and N1-acetoxy-2,2,5,5-tetramethylpyrrolin-3-oyl 2,3,4,6-tetra-O-benzyl-alpha- and -beta-D-glucopyranosylamines (9-alpha, beta) were synthesized in good yield by Schmidt's glycosylation method. Their subsequent O-debenzylation was proceeded successfully to give the desired products 1-alpha, and 1-beta in good yield, and 2-alpha in a low yield, without 2-beta by only short-timed hydrogenolysis in the presence of palladium-on-carbon (Pd-C) in a CHCl3-MeOH solvent system that included concentrated HCl. Upon enzyme-catalyzed hydrolysis, only 2-alpha was hydrolyzed by the esterase, while both of 1-alpha and 1-beta were not hydrolyzed by any other enzyme such as lipase.

Solution-state dynamics of sugar-connected spin probes in sucrose solution as studied by multiband (L-, X-, and W-band) electron paramagnetic resonance.

A multiband (L-band, 0.7GHz; X-band, 9.4GHz; and W-band, 94GHz) electron paramagnetic resonance (EPR) study was performed for two glycosidated spin probes, 4-(alpha,beta-D-glucopyranosyloxy)-TEMPO (Glc-TEMPO) and 4-(alpha,beta-D-lactopyranosyloxy)-TEMPO (Lac-TEMPO), and one non-glycosylated spin probe, 4-hydroxy-TEMPO (TEMPOL), where TEMPO=2,2,6,6-tetramethyl-1-piperidinyloxyl, to characterize fundamental hydrodynamic properties of sugar-connected spin probes.

In vivo temporal EPR imaging of the brain of rats by using two types of blood-brain barrier-permeable nitroxide radicals.

In vivo temporal EPR imaging was conducted on the brain of rats that received one of two kinds of blood-brain barrier-permeable nitroxide radicals via the tail vein-one is a water-soluble 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (hydroxymethyl-PROXYL); and the other is a non-water-soluble 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM). From temporal EPR imaging data, temporal changes in the distribution of the nitroxide radical in the cerebral cortex, striatum, and hippocampus in the brain were investigated. It was found that the half-lives of the three parts in the brain of hydroxymethyl-PROXYL are longer and their EPR signal intensities are greater than those of PCAM.

Clinical significance of a highly sensitive enzyme immunoassay of hepatitis B surface antigen using a novel electron spin resonance technique.

We developed a highly sensitive enzyme immunoassay (EIA), the p-AP/HHTIO method, that detects serum hepatitis B surface antigen (HBsAg) by measuring stabilized nitroxide radicals using a novel electron spin resonance technique [Matsuo et al. (1998) Free Radic Biol Med 25:929-935]. To demonstrate the clinical significance of this method and to reveal occult hepatitis B virus (HBV) infection in patients, we used the method to analyze serum samples of 30 patients with acute or fulminant hepatitis who were negative for HBsAg by standard EIA, and those of seven chronic HBV carriers who became negative for HBsAg during a follow-up period by standard EIA.