Antibiotiki最新文献

Distribution of drug resistance in Salmonella isolated from different sources was studied over time. The strains of S. typhimurium characterized by more pronounced resistance to antibiotics were mainly isolated from infants. Circulation of such strains in animals was extremely rare. Some genetic markers of such pathogens were investigated.

Sensitivity of 146 clinical strains of Candida albicans to nystatin, levorin and amphoglucamine was studied on solid media with the replica method. The strains were isolated from 79 patients with candidiasis of the oral mucosa. It was found that sensitivity of the fungi to the polyenic antibiotics was different which should be considered in treatment of candidiasis. On the basis of the mean MICs for the clinical strains and their distribution by the MICs it was shown that the activity level of levorin and amphoglucamine was higher than that of nystatin. During the treatment resistance of the Candida strains to the polyenic antibiotics increased and cross resistance developed which required application of other treatment means.

The effect of tetracycline, amphotericin B and kefzol on distribution of some proteins between the blood and lymph of the thoracic duct was studied on rabbits. Tetracycline was injected intramuscularly in the form of hydrochloride dissolved in 2% novocain in a dose of 25 mg/kg once or daily for 7 and 20 days. Kefzol (sodium cephazolin) was injected intramuscularly in a single dose of 100 mg/kg. Amphotericin B was injected intravenously in a dose of 1000 Units/kg once or for 5 days. The lymph samples were collected from the thoracic duct of rabbits treated with single doses of the antibiotics 1 and 24 hours after their injection. When the animals were treated with the antibiotics repeatedly the lymph samples were collected 24 hours after the last injection. The level of the total protein and the ratio of the protein fractions, i. e. albumins, alpha 1-, alpha 2-, beta- and gamma-globulins in the lymph and blood serum were determined. On the basis of these findings the protein coefficient (albumin/globulin) of the lymph and blood, the coefficients of the protein permeability of the blood vessels (R) and the constants of selective permeability of the blood capillaries (S) were calculated. It was shown that the shifts in the protein circulation between the blood and lymph had mainly the same trends independent of the antibiotics used and their retention time in the host. A significant decrease in the permeability of the blood vessel walls in respect to the total protein and gamma-globulins and a marked increase in their selectivity in passing of the protein molecules of different size were observed in all cases.

The effect of calcium pantothenate (CPN)B 4'-phospho-CPN (PCP), pantetheine (PT) and calcium S-sulfopantetheine (SPN) on acute toxicity of kanamycin sulfate was studied on albino mice. The above derivatives of pantothenic acid except PT lowered the antibiotic toxicity. The coefficient of the antitoxic effect (LD50/ED50) of SPN and PCP was 1.3-1.4 times higher than that of CPN. The combined use of kanamycin (1/5 of the LD50) with CPN, PCP or PT (30 mg/kg bw was equivalent to CPN) for 15 days prevented the increase in the total content of CoA and in the content of the fraction of free CoA and the precursors of its biosynthesis participating in the reaction of N-acetylation in the liver and brain. The contents of these substances were within the normal during the whole experiment. A certain increase in the activity of pantothenate kinase in the liver cytosol due to the use of kanamycin was eliminated by the simultaneous use of PCP and PT. The vitamin-containing compounds PCP and SPN were recommended for the clinical trials as agents preventing complications of kanamycin therapy.

The experiments with albino rats, Wistar rats and SHK mice showed that the combined use of amphotericin B and diacarb markedly potentiated the effect of the latter: the amount of the urine excreted within 6 h and the renal excretion of sodium ions increased 1.8 and 1.5 times, respectively. Analogous trends were observed in the experiments with stabilization of the animal water balance by 2 per cent water loading. The studies on rats with Pliss lymphosarcoma showed that the diuresis level in the tumor-bearing animals was 3 times lower than that in healthy rats. The treatment with 5-fluorouracil lowered this index more significantly. With the use of amphotericin B, diacarb and their combination the urination level came to normal. The cyclophosphamide therapy of mice with sarcoma 180 was accompanied by accumulation of water in the tumor tissue. The combined use of the cytostatic with the polyenic antibiotic and diuretic resulted in a significant lowering of this index. In rats with Walker-256 carcinosarcoma, the treatment with the above three drugs lowered the sodium ion concentration and increased the calcium ion concentration in the tumor tissue. At the same time the electrolyte level in some organs not affected with malignant tumor (spleen, thymus, liver and adrenal glands) returned to normal.

The seasonal characteristics of the efficacy of vitamin E and sodium selenite in tetracycline affections of the liver were studied on 128 noninbred male albino rats. It was shown that in comparison to vitamin E sodium selenite more actively retarded activation of lipid peroxidation in the liver and activation of alanine aminotransferase and alkaline phosphatase in the blood serum in autumn and winter. A more pronounced inhibition of the increased levels of the dienic conjugates and alanine aminotransferase was observed in spring and summer and malonic dialdehyde and aspartate aminotransferase in summer by tocopherol acetate as compared to sodium selenite. The level of the thiol-disulfide equilibrium on the separate use of the drugs in spring and summer was higher than the control one. However, it did not reach the control level in autumn and winter. The combined use of sodium selenite and vitamin E prevented the toxic effect of tetracycline on the liver in autumn, spring and summer. Still, in the winter no such prevention was observed. The mechanisms of the seasonal differences in the tetracycline effect on the liver and the efficacy of the antioxidants in such affections are discussed.

Sensitivity of 56 streptococcal strains of group B to 12 antibiotics was studied with the method of dilution in a special solid medium for cultivation of streptococci and with the method of agar diffusion in the same medium. All the strains were found to be sensitive to chloramphenicol, ristomycin and erythromycin. The predominating majority of the strains were sensitive to beta-lactam antibiotics and lincomycin. All the strains were resistant to aminoglycoside antibiotics, such as streptomycin and gentamicin. More than 85 per cent of the strains were resistant to tetracycline. Strains with multiple resistance to 2-7 antibiotics were detected. Satisfactory correlation between the two methods was observed. It was shown to be clinically advisable to determine the sensitivity of streptococci of group B to beta-lactam antibiotics, erythromycin and lincomycin.

Antitumor activity of doxorubicin made in the USSR was studied on mice in respect to three transplantable tumors (lymphadenosis NK/LI, sarcoma 37 and Ehrlich's carcinoma) and hemocytoblastosis La. Doxorubicin injected intravenously 4 times was shown to be highly active against the above ascites tumors. The highest inhibitory effect of doxorubicin was observed in respect to the development of Ehrlich's carcinoma. By the selectivity of the therapeutic effect on this tumor it was superior to rubomycin and carminomycin. A high antileukemic activity of doxorubicin in respect to hemocytoblastosis La was shown. In experiments with this leukemia, intravenous injection of doxorubicin provided a higher efficacy than intraperitoneal injection. When used intravenously in the doses equivalent by their toxicity doxorubicin was inferior to rubomycin in terms of the therapeutic effect on leukemia La. However, on intraperitoneal injection of the drugs rubomycin showed no such advantage. Doxorubicin made in the USSR did not differ by its antitumor activity from the analogous foreign drug.

The combined use of cephaloridin and cephalothin with sulfalen resulted in decreased binding of the cephalosporins by serum proteins and decreased rate of drug elimination in rabbits. It might be suggested that these two processes were interrelated. The decreased binding of the antibiotics by proteins in rabbits promoted an increase in the volume distribution of the drugs at the expense of a rise in the level of their penetration from the blood into the peripheral tissues.

Neutrophils and peritoneal macrophages of mice treated with prodigiozan and propranolol were studied for their capacity to reduce nitroblue tetrazolium and absorption and inactivation of the cells of staphylococci and dermatophytes. It was shown that prodigiozan stimulated bactericidal activity of phagocytes, amplified macrophage fungicidity, and decreased neutrophil fungicidity in respect to the dermatophytes. Propranolol increased the prodigiozan capacity for stimulation of the oxygen-dependent metabolism of phagocytes and absorption and inactivation of staphylococci. However, it inhibited inactivation of dermatophytes by phagocytes.