Importance of associated microorganisms in the development of acute pneumonia

Sputum samples obtained from 106 patients with acute pneumonia have been studied by the quantitative microbiological method. Different microbial associations have been shown to play an important role in the development of acute pneumonia (67.9%). Microbiological studies have revealed the prevalence of pneumococci in the etiological structure of the disease. Staphylococci, hemophilic bacteria and Neisseria have been found to take part in the development of acute pneumonia in a lesser number of cases and more often occur in combination with pneumococci or form different associations themselves. The so-called "etiological" type of microbial associations has been determined, two or three microbial species being isolated at high concentrations (10(6) and over) and the percentage of patients with such combinations being 59.7 +/- 5.8%. The analysis of the clinical course of the disease has revealed that the presence of different microbial species in patients linked, to a great extent, with the clinical picture of the disease. These data may be used for prescribing adequate etiotropic therapy and for prognostication. Quantitative bacteriological studies carried out in the dynamics of the disease permit timely detection of changes in the microflora of the respiratory tracts, the evaluation of the effectiveness of antibacterial therapy in the process of its implementation and the rational correction of therapeutic measures.     

Kinetics of the basic sections of the hemopoietic system in radiation chimeras]

During first 3 days after mice irradiation and syngeneic bone marrow transplantation in them the number of CFUs (about 0,5% of the injected cells) was stable, although the proliferation induction began 24 hours after transplantation. As it was shown by the method of "thymidine self-distruction". Twenty four hours later all the CFUs entered the mitotic cycle. On the contrary, the commited cells (granulopoesis precursors) compartment (CFUc) enters the logarithmic growth phase since the first day. The exponential growth of the CFUs number was observed from the 4th day simultaneously with the increasing of the proliferation rate of CFUc and the beginning of the recovery of the bone marrow cells total number. In late radiation chimeras (1 month after radiation and reconstitution) the total number of CFUs was 50--70% of the initial. The other hemopoetic parameters were in the normal limits.     

Analysis of the monocyte chemotactic response to lysophosphatidylcholine: role of lysophospholipase C

Previously, we reported that lysophosphatidylcholine (lyso-PtdCho), a component of oxidized low-density lipoprotein, was a monocyte chemoattractant (M.T. Quinn et al. (1988) Proc. Natl. Acad. Sci. USA 85, 2805-2809). Monocyte chemotaxis was also stimulated by lyso-platelet activating factor but not by platelet activating factor itself. In the present studies, we used other analogs of lyso-PtdCho to determine structural and metabolic features required for chemotactic activity. Although both D- and L-lyso-PtdCho stimulated chemotaxis, suggesting a lack of stereospecificity, studies using propanediol and ethanediol analogs of lyso-PtdCho suggested that a free hydroxyl moiety or an ester-linked fatty acid vicinal to the phosphocholine group of the lysophospholipid was required for the expression of activity. Incubation of [3H]choline-labeled lyso-PtdCho with monocytes resulted in the formation of labeled PtdCho, glycerophosphocholine (GPC), phosphocholine, and free choline, while resident peritoneal macrophages, cells which we show do not respond chemotactically to lyso-PtdCho, metabolized the labeled substrate to generate only labeled PtdCho and GPC; no labeled phosphocholine was found, suggesting a possible role for lysophospholipase C activity in the monocyte chemotactic response. Although monoacylglycerol, the product of lysophospholipase C hydrolysis of lyso-PtdCho, was not chemotactic for monocytes, diacylglycerol demonstrated chemotactic activity, suggesting that the subsequent acylation to diacylglycerol may be involved in the monocyte chemotactic response to lyso-PtdCho. Indeed, monocytes incorporated [3H]glycerol from [3H]glycerol-labeled lyso-PtdCho into di- and triacylglycerol. Based on these results, a model is proposed whereby the monocyte chemotactic response to lyso-PtdCho involves a sequence of metabolic steps which includes hydrolysis of lyso-PtdCho to monoacylglycerol and phosphocholine by lysophospholipase C followed by acylation of monoacylglycerol to diacylglycerol. Diacylglycerol would then act as an intracellular second messenger that could activate or facilitate the chemotactic response.     

Fleas of the Moiynkum Desert and their epizootic significance

The species composition of fleas in the Moiynkum Desert (Chu-Talas interfluve) and indices of their domination on different hosts was established on the basis of long-term observations (1973–2000). The most significant and prolonged changes in the population density of mass flea species (Xenopsylla gerbilli minax and Coptopsylla lamellifer, parasites of the great gerbil) occur in association with changes of the population density of rodents. Changes in the population density of rodents are usually observed year after similar changes in the population density of hosts. The leading role in the transmission of the plague vector belongs to the flea X. gerbilli minax.     

Solid-phase C-C and C-O bond forming reactions using 'traceless' pi-arene-chromium linkers

The scope of solid-phase reactions utilizing a 'traceless' pi-arene-chromium linker has been expanded to include the addition of organo-lithium reagents to a supported ester group, generation and alkylation of an enolate anion, and substitution via the Mitsunobu reaction. Immobilization of ortho-disubstituted polyfunctionalized arene chromium dicarbonyl species onto the solid support and subsequent, selective transformation is also reported.     

Synthesis and immunomodulating activity of new glycopeptides of glycyrrhizic acid containing residues of L-glutamic acid

New glycopeptides of glycyrrhizic acid (GA) containing Glu residues and their alpha-methyl esters, gamma-methyl esters, and alpha,gamma-dimethyl esters were synthesized using N,N'-dicyclohexylcarbodiimide in the presence of N-hydroxybenzotriazole or N-hydroxysuccinimide. Formation of amide bonds was observed on all the three COOH groups of GA, or selectively on the COOH groups of the GA carbohydrate part in dependence on the ratio of reagents and the reaction conditions. The GA glycopeptide with three residues of Glu(OH)-OMe at a dose of 2 mg/kg stimulated the production of antibody-forming cells in mouse spleen in comparison with the control. The GA glycopeptide containing Glu residues only in the GA carbohydrate part turned out to be an immunosuppressor. The glycopeptide of the 30-methyl ester of GA with residues of free Glu in its carbohydrate part increased the hemagglutinine titer at oral doses of 2 and 10 mg/kg. All the studied compounds had practically no effect on the delayed-type hypersensitivity in mice.     

Mechanism of the occurrence of postinjection abscesses

The decisive factor in the appearance of postinfection abscesses is the presence of damaged tissues, open to the penetration of microorganisms not only by the exogenic or endogenic route, but also by the so-called exoendogenic route, when they penetrate the body from the air via the upper respiratory ways and further into the blood and damaged tissues.     

Kinetics of the main sections of the hematopoietic system in the process of postradiational regeneration]

After a sublethal (200 rad) irradiation of mice there occurred during the first 24 hours in the bone marrow a marked reduction of the number of the stem (to 4%), committed precursors of granulocytes and macrophages (to 20%) and of the morphologically-identified cells (to 50%). Complete restoration of hemopoiesis was observed by the end of the 2 weeks after the irradiation and was primarily due to the exponential growth of the number of the stem cells and their intensified proliferation. An increase in the number of the committed precursors was retarded to the moment of restoration of the normal amount of cells in the bone marrow.