Secretion of periplasmic alkaline phosphatase (PhoA) encoded by the gene constituent of plasmids and the peculiar properties of cell envelope biogenesis in Escherichia coli strains with controlled synthesis of individual membrane phospholipids have been studied. Alkaline phosphatase secretion across the cytoplasmic membrane declines, while secretion into the culture medium intensifies under changed metabolism. The composition of anionic membrane phospholipids changes due to inactivation of the pgsA gene or regulation of its expression by environmental factor, as well as in the absence of the pssA gene which is responsible for the synthesis of the precursor for zwitter-ionic phospholipidphosphatidylethanolamine. This correlates with intensified secretion of exopolysaccharides and lower content of lipopolysaccharide and lipoprotein which are responsible for barrier properties of the outer membrane. The results suggest a possible coupling of protein secretion with biogenesis of cell envelope components at a level of phospholipid metabolism.
It is well known that the results of treating infections depend to a considerable extent on whether the infecting agent is only able grow outside the cells of the organism or can develop in the interacellular medium as well [1]. A situation when a part of the infection pool can localize and survive inside phagocytes is by no means rare in clinical practice. It is a common practice to distinguish between obligate
Interaction of antitumor and antibacterial drugs seems to be a very important factor probably influencing the efficacy of treating bacterial infections in patients in the course of antitumor chemotherapy. As is known, lethality in patients with a cancer diagnosis, resulting from a secondary infection on the background of special antitumor chemotherapy, is a rather common phenomenon [1 -3]. These cases frequently involve the intracell occurrence of pathogens, which is quite understandable if we take into account the immune deficiency arising in these cases, including that on the phagocyte level [4].
EXPERIMENTAL PARTThe experiments were performed on leukocytes from peripheral blood of healthy volunteers aged 18 -40, both intact and inoculated with St. aureus, and on leukocytes from patients with a diagnosis of breast cancer. The St. aureus strain was taken from clinical isolates. The minimum inhibiting concentration (MIC) and minimum bactericidal concentration (MBC) of antibiotics were determined by the method of double serial dilutions in an AGV medium [5]. According to these data, the MIC and MBC values for the antibiotics studied under a standard microbial load of 106 cells per ml AGV medium were as follows: gentamicin, 0.125 and 0.5 lag/ml; rifampicin, 0. I and 0.4 lag/ml; and erythromycin, 0.2 and 0.5 lag/ml, respectively. We have used the suspensions of 24-h cultures with the cell concentration characterized by the optical density. The bacteria were preliminarily opsonized with a normal blood serum. The antibiotics were represented by the following commercial drugs: rifampicin, erythromycin, gentamicin, doxorubicin, and dactinomycin. Their activities were referenced to the standard obtained from the Laboratory of Antibiotics Quality Control (State Research Institute of Drug Standardization and Control).
186The binding of antibiotics to polymorphonuclear human leukocytes was studied by incubating the cells (5 x 106 mi-l) with drug preparations at 37~ in a l-ml volume of medium 199 containing additives of gelatin (0. I%) and blood serum (5%) under aseptic conditions. The concentrations of the antibiotics tested were selected in accordance with their average therapeutic level in the blood serum [5,6]. The initial concentration of antibiotics was I0 lag/ml for the antibacterial drugs and 1 lag/ml for the antitumor ones. The samples were incubated for 30 min in plastic tubes placed in a temperaturecontrolled shaker. During this experiment, the viability of the cells was monitored using the Trypan Blue test. The cells were separated from the extracell liquid by filtration through Millipore SM membrane filters with a pore diameter of 5 lam. The residue was washed and the cells were lysed by repeated freezing-defreezing cycles in distilled water. The concentration of antibiotic was determined both in the cell lysate and in the filtrate. The coefficient of the antibiotic binding in the cell was calculated as the ratio of the drug concentrations inside and outside the cells. The ratio of intracell to extracell phases...
Purpose. Analysis of the cataract surgery visual outcomes and advantages of intraocular lens Synthesis SIPY.Material and methods. We have operated 43 eyes with cataract (38 patients) using Synthesis SIPY lens. Non-corrected visual acuity was 0.13 ± 0.08, best corrected visual acuity (BCVA) was 0.36 ± 0.1.Results. Following 7 months, secondary cataract was not detected in any patient, what explain the actuality of square edge optical part on 360° of perimeter. The lens is inserted in cartridge in factory sterile conditions which exclude the contact between lens and environment, reduce the risk of incorrect inserting of the lens in cartridge following pinching by the cartridge flaps and, subsequently, the haptic tearing off. This complex “lens-cartridge” excludes the damage of haptics and optic parts, which can occur in using other IOLs during the removal of the lens from the vial and placing it in the groove of the cartridge. Position of cartridge in injector centralizes the cartridge tunnel for the Accuject Pro injector plunger, thereby reducing the risk of pinching the rubber tip of the IOL haptic plunger during implantation. The diameter of the cartridge tip allows the IOL to be implanted through a 1.6 mm tunnel. The uncorrected visual acuity after surgery was 0.6 ± 0.28. The best corrected visual acuity was 0.78 ± 0.24.Conclusions. The Synthesis SIPY lens has a number of advantages: factory installation of the lens into the cartridge and compatibility of the cartridge with the Accuject Pro injector prevent damage to the IOL; Implantation of the Synthesis SIPY lens is possible through the 1.6 mm corneal tunnel; high diopter ranges from -10.0D to + 40.0D allows for maximum visual results.
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