A place of digital X-ray fluorography in the detection of lung diseases in the public health facilities of the Russian Federation

The paper shows the authors' opinion as to the use of digital X-ray fluorography (DXF) to detect pathology of the lung, primarily its tuberculosis and cancer from organizational-and-methodological and purely diagnostic standpoints. Based on a great body of data pooling 21,295 studies of patients, which comprised two (screening and routine clinical) groups, they authors state their views on the place and role of lung DXF in the work of public health facilities in the Russian Federation (RF). The objectivity of the authors' opinion is confirmed by the different nature of a lung abnormality detected by DXF at both the municipal and regional levels of the RF public health system and by a comparative analysis of the findings with those of film fluorography, routine X-ray study, linear tomography, X-ray computed tomography (XCT), and surgical evidence. The study has allowed the authors to express their opinion by recommending DXF as a method for primary diagnosis of lung diseases instead of film fluorography and routine X-ray study and to appreciate it in screenings. The authors' data indicate that XCT in its simplest variant rather than linear tomography should become the optimum method that specifies the diagnosis of lung diseases detected by DXT.     

Changing extracellular matrix of cells during development of suspension culture of Triticum timopheevii Zhuk

A study was made of the contents of the main polysaccharide fractions in the cell wall, and extracellular polysaccharides, and of the activity of cell wall enzymes during cultivation of suspension culture of cells of the winter wheat Triticum timopheevii Zhuk. It was shown that within 3 days of cultivation (a phase enriched in dividing cells), on the background of increased callose contents in plant cells, amounts of pectins and hemicelluloses extracted by 4N alkali decreased. The content of polysaccharides reached its initial level by the end of culturing. A parallel analysis of glycosidase activity in cell walls has shown their considerable activation at the stage enriched by dividing cells, which decreased at a transition of culture into the stationary level. The increased activity of hydrolyzing enzymes was combined with an increased efflux of extracellular polysaccharides into culture medium. The detected changes in polysaccharide composition of the cell wall at the first phase indicate its qualitative changes during cell wall reconstruction at the beginning of cytokines, whereas extensive expansion of cell wall was seen on the phase of elongation.     

Biologically Active Oligosaccharides from Pectins of Pisum sativum L. Seedlings Affecting Root Generation

Two physiologically active oligosaccharide fractions were isolated from pectin of Pisum sativum L. cell wall after its partial acid hydrolysis. These fractions displayed stimulating and inhibiting effects on root formation in thin-layer explants. The subsequent separation of these fractions by gel permeation and anion-exchange chromatography resulted in fractions with effective concentrations two orders of magnitude lower than the concentrations of the initial fractions. The resulting oligosaccharides displayed their effect on the earliest stage of the rhizogenesis associated with formation of root primordias. The rhizogenesis-inhibiting fraction suppressed cell division by 30-50%. The stimulating fraction mainly contained fragments of xyloglucan and galactan, and the inhibiting fraction contained fragments of xyloglucan, galactan, and arabinan. The polymerization degrees of the stimulating and of the inhibiting oligosaccharides were 10-11 and 5-6, respectively.     

Regulation of Callose Metabolism in Higher Plant Cells in vitro

Temporary accumulation of callose in suspension-cultured wheat (Triticum timopheevii Zhuk.) cells at the exponential growth phase was correlated with the mitotic index due to the formation of the cell plates in dividing cells. Callose disappeared in expanding cells owing to enhanced activities of endo- and exoglucanases. The exogluconase activity was reduced when the cells were treated with cycloheximide, an inhibitor of protein synthesis. A similar pattern was observed when elicitors experimentally enhanced callose synthesis. Apparently, in such cases, callose behaves as a temporary component repairing the cell wall. We presume that plant cells comprise a universal mechanism for regulating callose synthesis.     

Organizational and methodological approaches to using digital X-ray fluorography in the diagnosis of lung diseases in practical public health care of the Russian Federation

On the basis of a great body of information, the authors propose the most reasonable and effective organizational and methodological approaches to further actively introducing digital lung fluography into Russia's practical public health care. The paper discusses a diversity of topical problems associated with the practical use of digital X-ray fluorography (DXF), such as the assessment of its use depending on the level (municipal or regional) of public health care, methodological issues of its performance, current relationships of DXF and film fluorography; a place of DXF in the screening and routine clinical diagnosis of lung diseases. Great emphasis is laid on the role of DXF in the diagnosis of tuberculosis and cancer of the lung. The place and role of Russian manufacturers of digital lung fluorographs in the further development of SXF in practical public health care of Russia are also touched upon. The authors emphasize that replacement of film fluorography by digital one will present difficulties if regional and municipal health administrators do not take an active part in this matter.     

Oligosaccharin and ABA synergistically affect the acquisition of freezing tolerance in winter wheat

In this paper, we continue our studies of the previously discovered [O.A. Zabotina, D.A. Ayupova, O.N. Larskaya, O.N. Nikolaeva, G.I. Petrovicheva, A.I. Zabotin, Physiologically active oligosaccharides, accumulating in the roots of winter wheat during adaptation to low temperature, Russian Journal of Plant Physiology 45 (1998) 262] oligosaccharin (physiologically active oligosaccharide) GXAG, which stimulates the acquisition of freezing tolerance in winter varieties of Triticum aestivum L. The transient accumulation of GXAG in the tissues of winter wheat correlates with the temporal activation of cell wall glycosidases during the first hours of cold acclimation (2 °C). This finding suggests that the oligosaccharin is liberated as a result of the intensification of hemicellulose turnover. At low concentrations, GXAG initiates the acquisition of freezing tolerance in winter plants, in a manner similar to ABA, even at room temperature. The resultant effect of ABA and GXAG on the freezing tolerance of winter wheat depends on the sequence of pre-treatments with these two factors. When seedlings are pre-treated with GXAG a few hours before treatment with ABA, the effect is synergistic, and its impact depends on the duration of pre-treatment with GXAG. When ABA is applied first, the resultant effect on freezing tolerance is additive. The results obtained here lead to the conclusion that oligosaccharin, accumulating during the first hours of cold acclimation, functions as a partner of ABA during the initiation of freezing tolerance acquisition in winter plants. We hypothesize that GXAG increases cell receptivity to ABA signaling.     

Involvement of Oligosaccharides in Adaptation of Winter Wheat Seedlings to Subzero Temperatures

We studied the dynamics of endogenous content of biologically active oligosaccharides in the roots of winter wheat seedlings. Previously, these oligosaccharides proved to mediate the development of frost resistance during the first days of hardening (Zabotinaet al., 1998). The changes in their endogenous content can be described by a curve with a single peak observed 6 h after the onset of frost hardening. The capacity of these polysaccharides to increase frost resistance (LT₅₀was evaluated by leakage of electrolytes) when added to growth medium did not depend on the pretreatment duration (from 1.5 to 18 h) but decreased if they were introduced in the course of the adaptive response. Inhibition of the adaptive response by inhibitors of RNA and protein synthesis ceased in the presence of the oligosaccharides. We believe that the oligosaccharides that are products of metabolism of the cell wall polysaccharides are involved in adaptation to low temperature.