A procedure for the microdetermination of dihydroxyacetone (DHA) in biological fluids has been reported by us (1). Because of its relative time-consuming manipulations, a simpler procedure is sought in sacrifice of accuracy for brevity. This paper describes a new method which is based on the reaction between a-hydroxycarbonyl compounds and pyridine nucleotides to form addition compounds (2). Wi...

W/E RECENTLY reported a new colorimetric assay for glutamic-oxalacetic transaminase which involves coupling the oxalacetate formed in the enzymatic reaction with a diazonium salt (1, 2). Because of the greater specificity of the diazonium salt for the product of the reaction and the minimum number of manipulations involved, this procedure is simpler and more accurate than previously reported pr...

A method has been developed to measure aldehydes and ketones associated with atmospheric particles. Carbonyl compounds from particulate material collected on Teflon-coated glass-fiber filters were simultaneously extracted and derivatized with an appropriate 2,4-dinitrophenylhydrazine (2,4-DNPH) solution. The efficiency of this procedure utilizing various 2,4-DNPH concentrations and solvent comp...

Objectives: total serum vitamin C (L-ascorbic acid) concentration was measured in 90 pregnant women, 30 in each trimester (age range 18-35 years) and a control group of age-matched non-pregnant women. Methods: total serum vitamin C concentration was measured using the 2.4-dinitrophenylhydrazine method which involves the conversion of vitamin C to dehydroascorbic acid in the presence of copper (...

The relative performance figure of merits was investigated for the two most common analytical methods employed for carbonyl compounds (CC), for example, between high performance liquid chromatography (HPLC)-UV detector (with 2,4-dinitrophenylhydrazine (DNPH) derivatization) and thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) (without derivatization). To this end, the suit...

The atmosphere simulation chamber SAPHIR at the Research Centre Jülich was used to test the suitability of state-of-the-art analytical instruments for the measurement of gas-phase formaldehyde (HCHO) in air. Five analyzers based on four different sensing principles were deployed: a differential optical absorption spectrometer (DOAS), cartridges for 2,4-dinitrophenylhydrazine (DNPH) derivatizati...

Uyaku (Lindera strychnifolia, Sieb. et Zucc.) is used in traditional Asian medicine to treat stomach and renal diseases, neuralgia, rheumatism, and aging. In this study, the effects of lyophilized extracts on hydroxyl ((.)OH) and superoxide (O(2) (.-)) radicals were examined using an electron spin resonance (ESR) spectrometer with the spin trap, 5,5'-dimethyl-1-pyrroline-N-oxide. Inhibitory eff...

OBJECTIVE To investigate the effects of honokiol on induction of reactive oxygen species (ROS), antioxidant defense systems, mitochondrial dysfunction, and apoptosis in Candida albicans. METHODS To measure ROS accumulation, 2',7'-dichlorofluorescein diacetate fluorescence was used. Lipid peroxidation was assessed using both fluorescence staining and a thiobarbituric acid reactive substances (...

Protein profiling of cerebrospinal fluid in Guillain-Barrè syndrome (GBS), an acute and immune-mediated disease affecting the peripheral nervous system, was performed by two-dimensional electrophoresis. Significant modulated spots in GBS patients vs. control groups (a group of multiple sclerosis patients and one of healthy donors) underwent MALDI-TOF/TOF investigation. Inflammation-related prot...