Ultrastructural changes in cultured cells under the effect of Vibrio Cholerae hemagglutinin/protease.

Electron microscopic study of changes in cultured cells caused by Vibrio cholerae recombinant hemagglutinin/protease (HA/P) showed significant structural changes, most pronounced in HeLa and L-929 cells not forming a compact monolayer with tight junctions between the cells: formation of numerous vesicles on the cell surface and clasmatosis, vacuolation of the cytoplasm, swelling of mitochondria, clarification of their matrix and crist distortions, and increase in the number of lysosomes. Cytoplasm vacuolation predominated in MDCK culture, while clasmatosis was less intense. Addition of HA/P to CaCo2 cells forming a differentiated polarized monolayer, led to extension of cell-cell spaces not impairing tight junctions, swelling of mitochondria, cytoplasm vacuolation, and clasmatosis on the apical surface. These changes virtually completely coincided with those caused by the so-called NMDCY factor (non-membrane-damaging cytotoxin), described as new Vibrio cholerae toxin. These findings confirm our previous hypothesis about the identity of these factors.

[Ultrastructural changes of gastric superficial epithelium cells in chronic Helicobacter gastritis]. / Ul'trastrukturnye izmeneniia kletok poverkhnostnogo épiteliia zheludka pri khronicheskom khelikobakternom gastrite.

Electron-microscopic investigations were carried out in 22 specimens of biopsy material from pyloric and fundal parts of the stomach in patients with chronic Helicobacter gastritis. In 6 cases of normal mucosa Helicobacter pylori (HP) was absent both in the antrum and fundus. In chronic antral gastritis HP was found in both regions. Variants of HP adhesion to the epithelium and its interactions were studied. It is demonstrated that HP may penetrate into intercellular spaces and cell cytoplasm. Cell reciprocal reaction to adhesion and invasion was accompanied by hyperplasia of the microvilli, clasmatosis and "selfsanation" phenomenon. Differences between ultrastructural changes in the antrum and fundus were considered.

Ultrastructural changes in the nephron and renal protein cleaving function in suckling rabbits with experimental cholera.

Immature nephrons and the presence of a proteolytic system mediating extracellular protein digestion in the epithelium of proximal tubules are characteristic features of renal cortical ultrastructure in intact 10-12-day-old suckling rabbits. Cholera infection is accompanied by intensive cleavage of exogenous protein, which starts in podocytes and is completed in the cytoplasm of the proximal tubule epitheliocytes. Overload to nephron associated (in addition to urine production) with intensive extracellular hydrolysis impairs nephrothelium reactivity and increases its vulnerability to cholera exo- and endotoxins and their mediators.

[Ultrastructure of renal cortex in suckling rabbits with experimental cholera]. / Ul'trastrukturnye osobennosti izmenenii korkovogo veshchestva pochek krolikov-sosunkov pri éksperimental'noi kholere.

Development of experimental cholera in suckling rabbits is associated with appearance of alterations in glomerular filtration and tubular reabsorption of renal cortex. Ultrastructural changes of nephrons appear in the adhesion period and progress 24 hours later. In this case, particular vulnerability of the kidneys is associated with insufficient development of principal stages both in the cavity and membrane digestion in the gut, therefore, the kidney plays a role of one of the components of the protein-splitting system in the organism.

[Ultrastructural changes in the interstitial cells of the kidney medullary substance in suckling rabbits with experimental cholera]. / Ul'trastrukturnye izmeneniia interstitsial'nykh kletok mozgovogo veshchestva pochek krolikov-sosunkov pri éksperimental'noi kholere.

A culture of virulent selection of cholera vibrios L-top 5879 was introduced through the probe to suckling rabbits-pups 10 to 12 days old. Ultrastructural changes of interstitial cells and capillaries of kidney medulla were studied. During vibrio adhesion (4 hrs after the inaction) interstitial cells acquire dystrophic changes, lipid granules content reduces, while vascular permeability grows higher which suggests the presence of prostaglandin precursors elimination into blood flow. Cholera development (1-2 days later) is accompanied with progressing of signs of prostaglandin synthesis activation and their precursors passage into the vascular bed.

[Ultrastructural changes in atria dna small intestines of suckling rabbits in experimental cholera]. / Ul'trastrukturnye izmeneniia v predserdiiakh tonko i kishke krolikov-sosunkov pri éksperimental'no i kholere.

10-12-day old suckling rabbits received intragastrically culture of V. eltor 5879 and the resultant ultrastructural changes in the small intestine, atrial cardiomyocytes and capillaries were studied. In the period of cholera vibrio adhesion (4 hours after the culture administration) epithelial cells underwent hydropic degeneration. Degenerative changes due to cell vacuolization and contractile alterations were noted in cardiomyocytes of both atria. The atrial Na-uretic factor secretion prevailed over its synthesis in line with increased vascular permeability. The development of experimental cholera (on day 1-2) was characterized by balloon degeneration in the small intestinal epithelium. Numerous secretory granules were formed in the atrial cardiomyocytes without releasing peptides into the circulation. These changes are of compensatory nature and serve for liquid retention in the body. Microcirculatory disturbances take place at three levels: intravascular, endothelial and perivascular.

[Changes in the activity of endonucleolysis of nuclear DNA in children with acute leukemia]. / Izmenenie aktivnosti éndonukleoza DNK-kletochnykh iader pri ostrom leikoze u detei.

The previously established fact of low activity of Ca, Mg-dependent endonucleolysis of cell nucleus DNA in lymphoproliferative diseases (CME-activity) brought the authors to study intranuclear characteristics of lymphoid cells in childhood acute lymphoblastic leukemia (ALL). The intensity of DNA-endonucleolysis was measured in 0.7% agarose gel using electrophoresis. Peripheral blood and bone marrow samples from 13 untreated ALL patients and 23 children in remission were examined. The age of the patients ranged from 4 to 14 years. CME-activity before treatment appeared to be 2-10 times less than normal in 8 out of 13 patients. In bone marrow cell nuclei CME-activity was universally reduced 3-20-fold. In ALL remission endonuclease activity in blood and bone marrow cells returned to normal.

[Natural penicillin resistance of Francisella tularensis]. / Prirodnaia ustoichivost' Francisella tularensis k penitsillinu.

Altered viable forms of F. tularensis with spheroplast specific damages of the surface structures were isolated after the culture exposure to lithium chloride (0.5 and 1%). Study of natural penicillin resistance in the spheroplasts and bacterial forms of F. tularensis revealed their difference: the spheroplasts of the strains tested had a lower resistance to beta-lactam antibiotics than the bacterial forms while the activity of spheroplast beta-lactamase did not differ from that of the enzyme of the bacterial form and equalled 224 to 252 U/ml of the cell suspension. Therefore, on the model of the lithium-induced spheroplasts it appeared possible to show that the damages of the surface structures of the cell walls of F. tularensis changed the penicillin resistance level which was indicative of involvement of the F. tularensis cell walls in the phenomenon of the natural resistance to beta-lactams.

[Changes in Ca, Mg-dependent endonuclease of DNA in isolated nuclei of human lymphocytes in lymphoproliferative diseases]. / Izmenenie Ca, Mg-zavisimogo éndonukleoliza DNK v izolirovannykh iadrakh limfotsitov cheloveka pri limfoproliferativnykh zabolevaniiakh.

Ca, Mg-dependent endonuclease is one of the main DNAses of lymphocyte chromatin. It's activity is known to increase in the immune response and to decrease in spontaneous and experimental CLL. These observations became a basis for analysis of possible clinical meaning of it's enzymatic activity assay. Donors' peripheral blood lymphocytes being tested, normal level of endonucleolysis for men and children was defined. Except that patients with different clinical forms of lymphoproliferative diseases such as chronic lympholeukemia, non-Hodgkin lymphomas, Hodgkin's disease were observed. The results showed that Ca, Mg-dependent endonucleolysis activity was decreased in comparison to donors' one. Ca, Mg-dependent endonucleolysis activity was the same in the group of patients with non-malignant pathology and in donors' one. Successful treatment and remission state of our patients was associated with alteration of the Ca, Mg-dependent endonucleolysis activity to normal level as well as immunological parameters. That is why the activity of Ca, Mg-dependent endonucleolysis is suggested to be a new criterion of immune state and lymphocyte malignant transformation.