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.

[The combined action of octafluoropropane and bipolar ionized air].

An experiment with Wistar male rats was to look into the action of octafluoropropane (OFP, of 50 microg/m(3)) combined with bipolar ionized air (BIA) at a concentration of light air ions of 60,000 para-air in cm(3). The chamber experiment was 43 days long. Intoxication by OFP reduced body mass, as well as the erythrocyte count and hemoglobin level in peripheral blood. As for BIA, it appeared to bring these indices back to their normal values. Erythrocyte metabolism underwent phase-by-phase shifts; but breathing BIA mitigated these shifts markedly. As regards to erythrocyte metabolism in intoxicated animals, BIA had a compensatory effect Changes in the biochemical profile of blood plasma make us think, that BIA counteracts the OFP damaging action on the myocardium and, at the same time, aggravates impairment of metabolism in the liver and, probably, kidney. Variations in the spectrum and total content of higher fatty acids in the lung in the experiment were more pronounced in the event of exposure to OFP+BIA than to OFP alone. Also, the combined exposure increased the level of laurinic acid. Histological investigations of the liver, spleen, myocardium, trachea and the lung attested to the dystrophic damage of the liver, spleen plethora and reticular hyperplasia, and slight cloudy swelling of the myocardium attributed to OFP. After 14 days since the end of the experiment, histological changes were much less dramatic; in 39 days after the experiment all the changes were gone with the exception of weak emphysematosis. BIA had no effect on animals in the absence of OFP; neither was there any significant difference between control (intact) animals and those who breathed BIA in laboratory. To conclude, 50 microg/m(3) of OFP which falls far short of the existing maximum permissible levels, a strong toxic action on animals. Aside from mitigation of the OFP toxic action on erythrocytes and myocardium, BIA, when breathed with a long time, aggravated the metabolic disorders in the liver and lung provoked by OFP.

[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.

[Effect of prolonged inhalation of acetic acid vapors on several human functional parameters]. / Vliianie dlitel'noi ingaliatsii parov uksusnoi kisloty na nekotorye funktsional'nye pokazateli cheloveka.

Test subjects were continuously exposed to acetic acid vapors which form a constant component of enclosed atmospheres. The inhalation time was 15 to 22 days at concentrations of 5, 10 and 15 mg/m3 or 10 days at a concentration of 26 mg/m3. Physiological parameters showed statistically significant changes at concentrations of 15 and 26 mg/m3. It is suggested that the changes are not adaptive but have been produced by the adverse effect of acetic acid vapors on the human body. It is therefore concluded that the 15 mg/m3 concentration is threshold and the 5 and 10 mg/m3 concentrations are ineffective in terms of the tests used. The most sensitive method is measurement of hydrocarbons (C2-C5), especially ethylene, in the exhaled air.

[Change in the functional indices of animals during prolonged inhalation of acetic acid]. / Izmenenie funktsional'nykh pokazatelei u zhivotnykh pri dlitel'nom ingalatsionnom vozdeistvii uksusnoi kisloty.

Laboratory animals inhaled acetic acid vapors at a concentration of 86 to 27 mg/m3 for 3 to 35 days. It was found that the dose 36 mg/m3 inhaled for as long as 22 days constituted the minimal acting dose. The most sensitive parameters to be used in detecting the toxic effect of acetic acid were: treadmill run duration, open field activity, and ethylene, acetaldehyde and acetone concentrations in the exhaled air.

[Aerosol pollution of sealed manned quarters]. / Aérozol'nye zagriaznenie obitaemykh germetichnykh pomeshchenii.

The paper discusses the man's contribution to the formation of aerosol particles in manned enclosures. The data obtained in prolonged simulation studies suggest that man is the major source of aerosol contamination. The aerosol concentration and disperse composition are found to depend on the free volume per man. The paper presents for the first time the data on the rate of dust formation in manned enclosures.

[Microorganisms distribution in the aerosol of a manned sealed cabin and the effect of artificial air ionization on this process]. / Raspredelenie mikroorganizmov v aérozole obitaemoi germetichnoi kamery i vliianie na étot protsess iskusstvennoi aéroionizatsii.

In a manned enclosure the distribution of bacterial aerosol with respect to the size of particles is bimodal. Artificial bipolar ionization of the air may decrease the content of relatively large particles of bacterial aerosol, leaving particles with 2.0-0.6/micrometer in diameter in predominance. These properties of the bacterial aerosol structure may be of importance in the prophylaxis of aerogenic infections of cosmonauts.