Effect of combined preventive use of quadevit with antibiotics on the survival and humoral immune response in experimental studies]

An attempt to correct with quadevit immunodepression due to prophylactic administration of benzylpenicillin and gentamicin for 6 days provided positive results. There was a significant increase in the quantities of Ig 19S and Ig 7S after the animal immunization with the bacterial antigen, an increase in the number of the AFCs in the spleen of the albino mice in response to administration of sheep erythrocytes and an increase in the survival rate of the animals with salmonellosis. The simultaneous use of quadevit with cefamezine and erythromycin did not lower the unfavourable influence of the antibiotics on the immune status of the animals.     

Kiwifruit ameliorates gentamicin induced histological and histochemical alterations in the kidney of albino mice

Gentamicin is an antibiotic used worldwide for treating Gram-negative bacterial infections. Gentamicin causes nephrotoxicity in up to 25% of therapeutic cases owing to increased production of free radicals. Kiwifruit are nutrient-dense fruits that have proven effective for ameliorating many pathological conditions caused by oxidative stress. We investigated the possible prophylactic and therapeutic effects of kiwifruit on the changes in renal histology and histochemistry caused by gentamicin. Intramuscular injection of mice with gentamicin for 10 consecutive days was nephrotoxic as indicated by epithelial vacuolization, glomerular atrophy and tubular necrosis. Necrotic tubule cells lost most of their polysaccharides and structural proteins. Co-administration of kiwifruit with gentamicin prevented nephrotoxic changes to a modest degree. When administered subsequent to gentamicin intoxication, kiwifruit ameliorated significantly the histological and histochemical alterations caused by gentamicin. Our findings support the use of kiwifruit in cases of acute renal injury due to gentamicin.     

Antibiotics of the aminoglycoside group (gentamicin, sisomicin and amikacin) in the prevention and treatment of experimental plague]

Activity of aminoglycosides such as gentamicin, sisomicin and amikacin against plague microbe strains of natural origin was studied in vitro. It was also studied in prophylaxis and treatment of experimental plague infection in albino mice. The MAC of gentamicin and sisomicin for 50 strains of the plague microbe was 0.2-1.6 micrograms/ml. For the majority of the strains it was 0.4 micrograms/ml. The amikacin MICs were 0.4-3.2 and 0.8 micrograms/ml, respectively. High efficacy of gentamicin, sisomicin and amikacin was shown in prophylaxis and treatment of experimental plague infection in albino mice. The optimal doses of the antibiotics were determined. Under definite conditions such as the use of short-term regimens and higher intervals, advantages of sisomicin over gentamicin and amikacin in prophylaxis of experimental plague infection were observed.     

Gentamycin sulfate effectiveness and tolerance in patients with myelotoxic agranulocytosis]

Patients with myelotoxic agranulocytosis were treated with gentamicin administered intravenously as drop-wise infusions in a dose of 5 mg/kg body weight a day every 8 hours. The treatment course consisted of 7--24 days. No toxic reactions were observed. The therapeutic efficacy of gentamicin depended on the neutrophilic level and amounted to 50--60 per cent when the drug was used without identification of the causative agent. The prophylactic use of gentamicin decreased the infection incidence in patients with myelotoxic agranulocytosis, while the prophylactic efficacy of gentamicin was evident only when the number of the granulocytes was higher than 100/mm3 of the blood.     

Changes in the mitotic regime of cultures of continuous human amniotic cells (line A1) subjected to the action of decamethoxin]

The effect of decamethoxin solutions on the cultures of the permanent line of the amniotic human cells (A1) was studied. In concentrations of 1000 and 50-500 gamma/ml decamethoxin induced fixation of the cell layer and destruction of cells A1 respectively. Higher dilutions of decamethoxin from 10 to 0.1 gamma/ml induced suppression of the mitotic activity and arrest of the cells in the telophase. Possible causes of the changes in the mitotic regimen are discussed. Therefore, decamethoxin slackened the cell dividing process in vitro and blocked passage of the cells from the telophase into period G1 of the interphase.     

Therapeutic effect of some antibiotics on experimental staphylococcal infection and its correlation with in vitro activity of antibiotics in sub-inhibitory concentration against Staphylococcus aureus strains

The aim of the study was to demonstrate of whether the therapeutic effects of antibiotics depend on their in vitro activity in sub-inhibitory concentrations against staphylococci. Cloxacillin, gentamicin and lincomycin were used in the study. Groups of S. aureus strains, containing 6 strains with similar MIC values each but different sensitivity to sub-inhibitory antibiotic concentrations (sub-MIC) were selected (a total of 36 trains): i. strains increasing their sensitivity to phagocytosis and bactericidal activity of rabbit leukocytes after incubation with an antibiotic in 0.1 MIC concentration, ii. strains with sensitivity to the above factors unaffected by incubation with an antibiotic in 0.5 MIC concentration. The doses of staphylococci causing death of 90-100% of Swiss albino mice 10 days after i.p. infection were determined. The injected doses (LD 90-100) and various doses of antibiotics were used to determine ED50 values as well as the survival rate of the mice with experimental staphylococcal infections after treatment with these antibiotics. It was demonstrated that effective doses (ED 50) of the antiboitics were significantly lower when the antibiotics were administered once to mice infected with strains S. aureus sensitive to sub-MIC concentrations of the investigated antibiotics than for mice infected with strains resistant to their sub-MIC concentrations. Similar correlations were observed in mice which were given the antibiotics several times (for 7 days): the percentage of the surviving mice was higher in the group infected with sub-MIC sensitive strains. The therapeutic effect of cloxacillin, gentamicin and lincomycin demonstrated a significant correlation with the S. aureus strains used to induce the infections and their sensitivity, or lack of sensitivity in vitro, to phagocytosis and bactericdal activity of leukocytes in the presence of antibiotics in sub-MIC concentrations.     

Experimental study on the therapeutic effect of liposome-entrapped antibiotics in the treatment of destructive pneumonia]

The data on preparation of liposome-entrapped gentamicin sulfate and cefoperazone and their investigation on albino mice with staphylococcal destructive pneumonia are presented. Comparative study of the efficacy of gentamicin sulfate and cefoperazone in free and liposome-entrapped forms showed that immobilization of the antibiotics in phospholipid vesicles provided a 2-fold increase of their efficacy.     

Effect of subinhibitory concentrations of antibiotics on catalase activity of plague microbes]

It was shown that the presence of subinhibitory concentrations of ampicillin, cefotaxime or gentamicin in the cultivation medium had a marked inhibitory effect on the catalase activity of plague microbe. The effect depended on the characteristic features of plague microbe strains and the incubation temperature. When the cells of a virulent strain of the plague microbe Y. pestis 1300 were cultivated at a temperature of 37 degrees C on a medium containing the subinhibitory concentrations of ampicillin or cefotaxime, the pathogen virulence for albino mice significantly decreased.     

Evaluation of outcomes of combined specific prophylaxis with the antibiotic resistant immunogenic plague pathogen strain and emergency prophylaxis with aminoglycosides in the experimental plague model in white mice]

It was shown that aminoglycosides (streptomycin, kanamycin, gentamicin, sisomicin, tobramycin, amikacin) prevented manifestation of postvaccine immunity in albino mice immunized by vaccine strain Yersinia pestis EV. Avirulent strain Y. pestis 363 Monr with chromosome resistance to aminoglycosides of the 1st, 2nd and 3rd generations provided manifestation of antiplague immunity when streptomycin, kanamycin, gentamicin and amikacin were administered for prophylaxis. ED50 achieved 1.0-1.2 x 10(3) CFU and in control group (without treatment) 9.3 x 10(2) CFU. Gentamicin and amikacin were highly effective for experimental plague prophylaxis (90-100% animal survival), but inhibited development of postinfective immunity. Protective index (PI) value was 1.1 x 10(2). It was demonstrated that combination of specific prophylaxis (Y. pestis 363 Monr) and emergency prophylaxis with aminoglycosides in albino mice infected with approximately 1000 LD50 of virulent strain Y. pestis 358 (5 hours after infection) was highly effective and provided protective effect against subsequent infection with plague pathogen. Value of PI was 1.1 x 10(5) and practically did not differ from PI (1.7 x 10(5)) in control group (intact mice, immunized with strains EV [symbol: see text] 363 Monr).     

Chemotherapeutic effectiveness of doxycycline in experimental Q fever

Comparative chemotherapeutic efficacy of doxycycline administered orally or parenterally was studied on a model of experimental Q fever in guinea pigs and albino mice. The advantage of the parenteral use of the antibiotic was observed only in the treatment of the albino mice. Optimization of the doses and time of doxycycline use providing the maximum therapeutic effect and the required levels of the complement binding antibodies was achieved with employing the multifactorial analysis.     

Effect of gentamycin in combination with prodigiozan on the immunological reactivity of the body

The effect of gentamicin sulphate and its combination will prodigiozan on antibody formation in experiments and the levels of the immunobiologic reactivity of patients with purulent inflammatory processes was studied with a purpose of developing rational schemes of antibiotic therapy of infectious diseases. A decrease in the titers of the antibodies to Aeromonas and the number of antibody-forming cells in the spleen was noted on repeated administration of gentamicin to albino mice in a dose of 20 mg/kg. This was prevented by the use of prodigiozan in a dose of 500 micrograms/kg once every 4 days. The use of gentamicin in patients with purulent inflammatory diseases in doses of 40 or 80 mg twice a day for 7--10 days had no significant effect on the titers of IgA, IgG, IgM, lysozyme blood serum levels, serum bactericidal activity and absorption activity of the peripheral blood neutrophils. Still, it induced a marked suppression of the neutrophil digestive capacity as compared to the initial levels, especially on administration of gentamicin in a dose of 40 mg twice a day. An increase in the level of IgM and no suppression of the neutrophil digestive capacity were noted after completion of the therapy in the patients treated with gentamicin administered in a dose of 40 mg twice a day and prodigiozan administered in a dose of 50 micrograms once every 4 days. It is recommended to use prodigiozan in combinaed therapy with gentamicin for correction of the changes in the specific and nonspecific protective forces of the host.     

Triazavirin prophylactic efficacy against influenza virus A (H5N1)

The experimental study of the prophylactic efficacy of Triazaverin against the experimental form of the influenza virus A (H5N1) on albino mice intranasally infected with the influenza virus A/Chicken/Kurgan/Russia/02/05 vs. the reference drugs Tamiflu, Remantadin and Arbidol showed that in doses of 1 to 100 mg/kg it was efficient in the animal protection from death. The drug was also efficient in the urgent prophylaxis. Triazaverin effectively inhibited the influenza A virus multiplication in the lungs of the albino mice.     

Search for inhibitors of West Nile virus among antibiotics]

The activity of 24 antibiotics was studied in treatment of albino mice with experimental encephalitis caused by West Nile virus. The antiviral activity of gentamicin and kanamycin was stated. The survival rate of the animals 19. contaminated with 10-100 LD50 of the West Nile virus and treated parenterally with gentamicin in a dose of 80 to 400 micrograms/mouse was higher than that in the controls by 29.5 to 100 per cent and depended on the drug regimen. The efficacy of kanamycin was lower. The chemotherapeutic indices of gentamicin and kanamycin amounted to 100 and 10, respectively. Since there are no schemes for chemotherapy of the infection caused by the West Nile virus and the respective vaccines are not available the use of the antibiotics and gentamicin in particular appears to be promising in the disease prevention and treatment.     

Rapid evaluation of the effectiveness of antibacterial drugs in experimental tularemia

Rapid estimation of the protective effect of antibacterial drugs on Fransiella tularensis for not more than 2 days was shown possible in experiments on albino mice infected with tularemia. High efficacy of aminoglycosides (kanamycin, gentamicin, streptomycin, amikacin, netilmicin, tobramycin, sagamycin, ribostamycin and sisomicin), tetracyclines (tetracycline, doxycycline, minocycline and methacycline), rifampicin, phosphomycin and oxolinic acid was determined with the recommended rapid method. Amoxycillin, ampicillin, piperacillin, carbenicillin, erythromycin, levomycetin, cefradine, cefmetazole, cefatrizine, cefoxitin, cefsulodin and bactrim (biseptol) proved to be inefficient against the tularemia causative agent.     

Comparative effectiveness of antimicrobial action of antiseptics against pathogens of chronic purulent otitis media]

Comparable antimicrobial and disinfecting action of decamethoxine and silver preparations on pathogens of chronic purulent otitis media (CPOM) was studied. The clinical isolates of staphylococci proved to be most sensitive to decamethoxine whose MBcC conformed to 16.5 micrograms/ml. The antimicrobial action on Proteus spp. and Pseudomonas aeruginosa was less pronounced. The required concentrations for bactericidal action on these pathogens were 69 and 93.5 micrograms/ml, respectively. The antimicrobial activity of the silver preparations such as poviargol, collargol and protargol was low. Depending on the microbial species, the bactericidal effect of the silver preparations was 12-235 times lower than that of decamethoxin. It was also shown that decamethoxin had a high disinfecting action on CPOM pathogens. It was noted that decamethoxin had a marked ability to increase the bactericidal action of poviargol (by 2-14 times) and its disinfecting action (by 2 times) on Proteus spp., E. coli and Ps. aeruginosa.     

Action of tetracyclines on the pseudotuberculosis microbe in vitro experiments and their effectiveness in experimental pseudotuberculosis in white mice]

227 out of 228 strains of pseudotuberculosis microbes studied in vitro proved to be sensitive to tetracyclines. The MIC of tetracycline and morphocycline ranged within 0.25--25 gamma/ml. The MIC of chlortetracycline and oxytetracycline was somewhat lower, i. e. 1--50 gamma/ml. When administered intramuscularly all the tetracyclines had pronounced therapeutic effect in experiments with albino mice infected with the antibiotic sensitive strains of J. pseudotuberculosis. Chlortetracycline proved to be the most active drug in treatment of albino mice per os.     

Comparison of silver sulfadiazine and gentamicin for topical prophylaxis against burn wound sepsis.

Daily prophylactic application of either 1.0% silver sulfadiazine cream or 0.1% gentamicin cream was compared for effectiveness in preventing bacterial colonization of burn wounds and sepsis. Pseudomonas aeruginosa colonized the wounds of 37% of the 38 patients treated with silver sulfadiazine and 30% of the 33 patients treated with gentamicin; gentamicin-resistant P. aeruginosa colonized the wounds of 21% of the patients treated with gentamicin. Staphylococcus aureus colonization occurred in 55% of the patients treated with silver sulfadiazine, whereas colonization with Candida species occurred in 58% of the patients treated with gentamicin. Although gentamicin-resistant organisms caused no deaths their repeated appearance resulted in discontinuation of prophylaxiz with gentamicin cream. The next year P. aeruginosa strains resistant to gentamicin were isolated from burn wounds of only two patients who had not previously received parenteral therapy with gentamicin or tobramycin. Gentamicin cream should be reserved for treating patients with wounds infected by gentamicin-sensitive P. aeruginosa and those allergic to sulfa drugs. For most patients with burn wounds silver sulfadiazine is safe and effective as an antibacterial agent for topical prophylaxis.     

Biological effects of phytoecdysteroids and chronic low-dose irradiation

The influence of serpistene in dose of 5 and 50 mg/kg on chronic low-dose gamma-irradiation (22.6 cGy) effects on cytogenetic (abnormal sperm cell, marrow bone micronucleus) and function and morphology (thyroid and adrenal glands) parameters of mice was estimated. The serpistene modifies effects of gamma-irradiation depends on the administration regime and a dose of the substance. The most expressive radioprotective effect on endocrine organs after serpistene prophylactic administration was found. The prophylactic dose was 5 mg/kg for adrenal gland and both doses--for thyroid gland. The most expressive radioprotective effect on marrow bone cells after serpistene therapeutic administration in a dose of 5 mg/kg was found. The most expressive antimutagenic effect on somatic and germinal cells of prophylactic and therapeutic administration in a dose of 50 mg/kg was found.     

Nerve-blocking properties of antibiotics]

Comparative data on the neuroblocking activity of antibiotics of various groups in acute experiments on albino mice and narcotized cats are presented. It was found that according to the impairments in the neuro-muscle conductivity the drugs were arranged in the following descending order: polymyxin B, neomycin, gentamicin, streptomycin, lincomycin and kanamycin. The streptomycin derivatives were approximately 2 times less toxic than streptomycin. The problems of the mode of action of the antibiotics on conductivity of excitation in the neuro-muscle synapses are discussed.     

Antiviral activity of oral ultralow doses of antibodies to gamma-interferon: experimental study of influenza infection in mice]

Course intragastric administration of ultralow doses of human gamma-interferon antibodies (ULD anti-IFN-gamma) to intact mice resulted in an increase of endogenous IFN-gamma production by the animal lymphocytes. Oral prophylactic administration of ULD anti-IFN-gamma significantly lowered the influenza virus concentration in the animal lungs at the initial stage of the aerogenous infection: in 2 (p = 0.05) and 3 (p = 0.07) days after the contamination. The therapeutic antiviral effect of ULD anti-IFN-gamma in mice with influenza was evident from a significant decrease of the influenza virus concentration in the lungs of the animals on the 4th (p = 0.05) and 5th (p = 0.07) days after the contamination. The antiviral effect of ULD anti-IFN-gamma after the prophylactic and therapeutic use is likely provided by induction of endogenous IFN-gamma.