Flow cytometry in the exploration of the physiopathology of occupational lung disease

Flow cytometry enables identification of sporophytic eliciting stress treatments in gametic cells

Flow cytometry was used to quantify the effect of individual and combined stress treatments on elicitation of androgenesis by analyzing the relative nuclear DNA content of in vitro cultured microspores of Pisum sativum L. Differences in relative nuclear DNA content of microspores within anthers after stress treatments were clearly evident from the flow cytometry profiles, and permitted us to predict whether a combination of stresses were elicitors or enhancers of androgenesis. This is the first report to assess the effect of various stress treatments in a plant species based on relative nuclear DNA content and to use this information to categorize them as 'elicitors' or 'enhancers'. Flow cytometry represents a simple, quick and reliable way to analyze and discriminate the effect of various stress treatments on elicitation of androgenesis. These results form a solid basis for further efforts designed to enhance responses and to extend double haploid technology to other legumes.

Flow cytometric analysis of the oxidative status in human peripheral blood mononuclear cells of workers exposed to welding fumes

Flow cytometry is a simple analytical technique that identifies, counts, and characterizes cells. The oxidative status of cells is influenced by many exogenous sources, such as occupational exposure to welding fumes. This study evaluated flow cytometry as a method to determine the oxidative status of male welders (n = 15) occupationally exposed to welding fumes. Flow cytometric analysis of reactive oxygen species (ROS) was carried out in peripheral blood mononuclear cells (PBMC) by using the probe 2, 7-dichlorodihydrofluorescein diacetate (DCFH-DA). Lipid peroxidation was measured by the decrease of fluor-DHPE fluorescence and intracellular glutathione (GSH) levels by using mercury orange. All of the parameters were also observed under a confocal microscope. The oxidative stress ratio was calculated from the oxidative damage and the antioxidant capacity to give an accurate account of the cellular oxidative status. ROS and lipid peroxidation levels were elevated by approximately 87% and approximately 96%, respectively, and GSH levels lowered approximately 96% in PBMC of workers exposed to welding fumes compared with non-exposed controls. The oxidative stress ratio was significantly higher (p < 0.001) in the exposed group. Flow cytometry can be useful for the measurement of cellular oxidative stress in somatic cells of workers exposed to welding fumes and other occupational settings. Calculating an oxidative stress index may be useful in predicting disease outcomes and whether preventative control measures are efficient.

In vivo bioassays of acute asbestosis and its correlation with ESR spectroscopy and imaging in redox status

In vivo electron spin resonance (ESR) spectroscopy and whole body imaging were used to investigate the toxicity of biological reactions and organ specific oxidative changes associated with the development of acute asbestosis. Pathogen-free mice were exposed to 100 microg of crocidolite asbestos suspended in 50 microL of a 0.9% NaCl solution by aspiration. The bio-assay group had broncho-alveolar lavage (BAL) and serum draws performed on control and treated mice at 1, 3, and 7 days post-instillation. The ESR spectroscopic measurements and whole body imaging were performed with a separate group of mice at the same time points. Bio-assays included measurements of albumin, lactate dehydrogenase (LDH), N-acetyl-beta-D-glucoaminidase (NAG), and catalase in acellular lavage fluids, and total antioxidants status in blood serum. ESR spectroscopic and imaging measurements were performed after intraperitoneal injection of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-15N-1-oxyl (TEMPOL) or 3-carbamoylproxyl (3-CP) nitroxides at a final concentration of 344 mg/kg body weight. Albumin showed a significant increase in BAL fluid at the 3 day exposure time point. The presence of this protein in lavage fluid indicates that the gas/blood barrier has been damaged in the lung. LDH in BAL fluid also exhibited a significant increase at 3 days post-exposure, an indication of enhanced cell membrane damage in the lung. Similar results were observed for NAG, a lysosomal enzyme, implying activation of phagocytic cells. Contemporaneously with the development of acute asbestosis at day 3 post-exposure, there were significant increases in the levels of total antioxidants in the serum and catalase in the BAL fluid. Significant impairment in the ability of asbestos exposed animals to clear TEMPOL radical during acute disease progression was evident at days 1 and 3 post exposure. ESR image measurements provided information on the location and distribution of the 3-CP label within the lungs and heart of the mouse and its clearance over time. Bioassays in concert with ESR spectroscopy and imaging presented in this study provide congruent data on the early acute phase of pulmonary injury and oxidant generation in response to asbestos exposure and their decline after 7 days. The increased levels of total antioxidants in the serum and catalase in BAL fluid correlated with the reduction in the clearance rate for TEMPOL, suggesting that a change in the redox status of the lung is associated with lung injury induced by asbestos.