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Distinct increase in content of ATP was found in preparations of enriched with plasmatic membranes particles from rat thymus T lymphocytes and from human peripheric blood T lymphocytes after their incubation with interleukin-2 as compared with controls which did not contain the peptide. The phenomenon observed was manifested only if these particles from T cells were preincubated with concanavalin A (2 min, 40 micrograms/ml), which is required to expression of the receptors for interleukin-2. The membrane-bound ATP, formed after the interleukin-2 effect on receptors of T lymphocytes, appears to serve as the secondary messenger activating protein kinase C.

P. aeruginosa pneumonia was induced in experiments on rats with stage III-IV thermal burns occupying 18-20% body skin surface. Electron microscopy was used to study the pathways of microorganism invasion from the lungs to the blood. The three main pathways of invasion were discovered: via the dilated intercellular gaps and degenerated basal membrane of the capillary endothelium; via the cytoplasmic channels, and via cell cytoplasm due to incomplete phagocytosis and destruction of macrophages and endotheliocytes. Endocytobiosis of P. aeruginosa in dystrophic pulmonary cells has been demonstrated as one of important factors of the pathogenesis of bacterial invasion.

Electron microscopic examinations of the white blood in 7 patients with purulent wounds and clinical manifestations of sepsis and in 1 patient with purulent wounds complicated by the development of bacterial shock as well as of the ultrastructure of bacteria isolated from the wound content of the patients were carried out. The controls consisted of electron microscopic examinations of the blood from two donors. The blood of patients with sepsis was found to contain free microbial cells and those phagocytized by neutrophilic leukocytes. Free bacteria formed large colonies enveloped in a strong membrane in the blood. Some leukocyte-phagocytized microbes underwent lysis, the others, surrounded by an envelope were located in large vacuoles in the blood cell cytoplasm (incomplete phagocytosis). Numerous microbial cells both free and phagocytized were particularly frequently found in bacterial shock accompanied by the clinical picture of most acute septicemia.

The myocardium of the right and left heart ventricles of rats was studied during 2.5-month adaptation to high-pressure chamber hypoxia (at an altitude of 6000 m). During varying time of rats' adaptation to hypoxia, destructive and compensatory-adaptive processes in the cardiomyocytes were seen concurrently. In long-term adaptation to high-pressure chamber hypoxia there developed hypertrophy largely of the heart right ventricle on account of hyperplasia and hypertrophy of individual intracellular organelles, particularly of mitochondria. The animals who adapted to high-pressure chamber hypoxia showed enhanced metabolic processes in the myocardium.

Proton magnetic relaxation with measuring the time of spin-screen relaxation (T1) was used to study the time course of derangement of organ and tissue flooding after stage IIIB experimental burn of 15% body area. To examine the structures of the microcirculatory vessels, use was made of electron microscopy of the organs. The internal organs under study demonstrated a significant long-term (up to 49 days) increase in flooding: in the liver and kidneys, it occurred since the first day after burn, while in the lungs, myocardium and brain, since the 7th day. The results indicate the parallelism of the changes in the T1 and electron microscopic alterations in the histohematic barriers. Proton magnetic relaxation enables a more rapid and more convenient assay of the changes in tissue flooding as compared to the method of drying at high temperature. Therefore, it may be applied to the assessment of the efficacy of different therapeutic means.

Electron-microscopy investigations of the small intestine mucosa in white rats with deep thermal burns of 18-20% of the body surface showed that already in early periods following the trauma grave thermal burns caused structural desorganization of the enterocytic barrier and invasion of the intestinal microflora. Damages of the wall of capillaries of the small intestine mucosa, being in themselves manifestations of generalized lesion of the histo-hematic barriers in burns, contributed to further invasion of microflora and its vital activity products into the blood. During the investigation a morphological picture of the phenomenon of endotoxinemia and bacteriemia developed already in the early periods of the burn trauma was established.

Under conditions of a severe burn trauma the experimental P. aeruginosa pneumonia is accompanied by marked destructive changes of all the elements of the hemato-aerial barrier and its increased permeability. At the same time, because of sharp inhibition of the intracellular lysis of bacteria in all elements of the pulmonary reticuloendothelial system, a long-term retention of the pathogenic microflora in the pulmonary tissue is observed. The combination of these factors results in microflora invasion of the blood channel of the lungs, and in this way the lungs acquire an important role as additional portals of entry of infection in severe burn trauma.

The metabolism of RNA in cells of callus 4 and 7 days following the fracture was studied. At the three stages of differentiation of osteogenic cells--preosteoblasts, differentiating osteoblasts, and osteoblasts--there was noted a similar dynamics of synthesis and transfer of RNA. One and a half hour after administration of a precursor of RNA--uridine-5H3 grains of silver concentrated predominantly above the nuclei, nucleoli being marked most intensively. Four hours after the administration of the precursor the total number of grains above the cells increased, mostly above the granular endoplasmatic reticulum; density of grains over the nuclei at this time did not change significantly, whereas that over the nucleoli decreased notably. The relationship between the observed features of the RNA metabolism and various stages of differentiation of osteogenic cells is considered.

Experiments carried out on 134 newborn mice showed that influenza virus and staphylococcus infection and their combination induces local necrosis in the myocardium. Morphometric measurement has shown that the extent of necrotic changes amounted with the action of the influenza virus to 1.37%, with the action of staphylococcus to 1.4% and with their combined action to 1.8%. Electron microscopy revealed dystrophic changes in cardiomyocytes with subsequent intracellular regeneration.