High-sensitivity express immunochromatographic method for detection of plant infection by tobacco mosaic virus.

A highly sensitive express immunochromatography method for molecular diagnosis of plant virus infections was elaborated on the example of a model object - tobacco mosaic virus (TMV). The analysis time does not exceed 5 min, and the lower limit of TMV detection in non-clarified leaf extract (2-4 ng/ml) is comparable with the sensitivity of the enzyme-linked immunosorbent assay of the virus. A single measurement requires 0.1-0.2 ml tested solution (extract from 10-20 mg of leaf material). The sensitivity of TMV determination in the leaf tissue extract was increased by more than one order of magnitude using signal enhancement by silver and is 0.1 ng/ml. In this case, analysis time did not exceed 25 min. The simplicity of this method makes it especially convenient in express diagnosis of numerous analyzed specimens. The prototype of a diagnostic kit for serial analyses of plant viral infections both in laboratory and field conditions was elaborated.

[Octafluoropropane inhalation toxicity].

Wistar rats were used to study inhalation toxicity of octafluoropropane (OFP, freon-218) at the following concentration: 300 g/m3 (4-hrs), 30 g/m3 (0.5 to 4 hrs), 3 g/m3 (8 hrs), and 0.3 g/m3 (16 hrs). According to the histological analysis, OFP at the concentrations of 300 and 30 g/m3 had a politrophic toxic effect. Target organs were the lung, trachea, bronchus, heart, kidney, and the adrenaL There were dystrophic and necrobiotic lesions in the upper airways epithelium. Subacute and chronic vesicular bronchiolitis developed on days 7 and 14, respectively. Visceral organs and brain were found plethoric and the lung was found hemorrhagic. Similar lesions were seen in the trachea, bronchus, lung, liver, spleen, kidney, adrenal, heart, and the brain. Lipid redistribution was observed in the adrenal cortex and vascular reactions of renal tissue with juxtamedullar blood shunting. Toxicity of small OFP concentrations (3 and 0.3 g/m3) was distinguished by an extended aftereffect, these concentrations did not cause visible pathomorphologic changes but gave rise to an extended pathologic process detectable by biochemistry. In all concentrations, OFP impacted erythrocyte metabolism changing the lipid composition of cell membrane and activating membrane-bound adenosinetriphos-phatases. The activities of hepatocyte and myocardiac cytoplasmatic enzymes were altered in blood plasma. Increased malonic dialdehyde in blood plasma and decreased cell antioxidant GSH in erythrocytes suggested exaggerated lipid peroxidation. These data point to the necessity of revising the existing limits for OFP concentrations in air of populated areas, working areas, and closed human environments.