ABSTRACT
AIM: Detection of bactericidal effect of pulse-periodic corona discharge (PPCD) on cells and biofilms of Escherichia coli M17. MATERIALS AND METHODS: A gas-discharge device was created based on PPCD in air with power supply parameters: amplitude values of voltage of 30 - 60 kV, pulse repetition rate of 250 - 400 kHz. Ultrastructure changes in cells and biofilms of E. coli M17, affected by PPCD, generated in air, were studied by typical methods of transmission electron microscopy. RESULTS: Disturbances of integrity of surface and abyssal structures of biofilms, as well as changes of morphological properties of E. coli M17 cells, characteristic for sub-lethal heat impact, were detected. Destructive changes of bacterial cells were developed by formation of focal disturbance of cytoplasmic membrane, extension of periplasmic space, formation of globular structures, characteristic for heat effect, and destruction of cytoplasm. CONCLUSION: Bactericidal effect of PPCD on E. coli M17 cells as part of biofilms was shown. Destructive morphological changes in cells and biofilms of E. coli M17 after the effect of PPCD were detected for the first time on electron-microscopic level.
Subject(s)
Biofilms/drug effects , Cell Membrane/drug effects , Escherichia coli/drug effects , Periplasm/drug effects , Plasma Gases/pharmacology , Biofilms/growth & development , Cell Membrane/ultrastructure , Electricity , Escherichia coli/growth & development , Escherichia coli/ultrastructure , Hot Temperature , Microscopy, Electron, Transmission , Periplasm/ultrastructureABSTRACT
It has been shown that in the ontogenesis of human placenta there occur regular changes in the percentage of the villi of various calibre having different interrelationships between the trophoblast, the connective tissue stroma and the fetal vessel. The changes of the number of chorial villi affected by fibrinoid and containing blood vessels under the trophoblast in late toxicoses of women and the anemic syndrom are analyzed (treated and not treated groups of women suffering from different forms of toxicosis were compared). An increased amount of chorial villi having blood vessels under the trophoblast is noted which is a morphofunctional feature of compensatory-adaptational alterations. Possible ecologo-evolutionary approaches to clearing the biological significance of adaptational changes of morphogenesis of the human placenta in pathological pregnancy are shown by the example of the analysis of morphological peculiarities of the placenta of the dolphin.
