摘要:

The influence of three categories of anti-cancer agents on competence development and on the binding of homologous DNA to cells have been studied in the Bacillus subtilis transformation system. Treatment of cells developing competence with testolactone resulted in a slight enhancement of transformation at high doses (50 and 100 μg/ml) of the drug, but this process was inhibited at 25 μg/ml. DNA binding was unaffected by this drug. DNA-interacting agents (daunomycin, prospidine, peptichemio and mithramycin) usually inhibited DNA-mediated transformation in a higher extent than DNA binding. Antimetabolites of DNA synthesis were also tested: dacarbazine did not greatly inhibit the binding and expression of donor DNA. 5-Fluorouracil appeared to slightly enhance transformation at low levels (1 μg/ml), although it was inhibited at higher dos

ISSN:0009-3157    

DOI:10.1159/000237922

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

3′-Deoxyadenosine, 3′-amino-3′-deoxyadenosine (3′3′), nine derivatives therefrom, two derivatives of 5′-amino-5′-deoxyadenosine and three derivatives of 3′, 5′-dideoxyadenosine were tested in cell culture for antiviral activity against three DNA viruses: adenovirus 5, herpesvirus hominis 1, and vaccinia virus. Cytotoxicity was also assessed. (3′3′) derivatives affected the multiplication of all three viruses similarly. Those which were effective were also cytotoxic at the same or slightly higher concentration. Substitution or other molecular modification of (3′3′) tend to lower the biological activity. The presence of an adenosine deaminase inhibitor enhanced both antiviral activity against adenovirus 5 and cytotoxicity in (3′3′) compounds, but not in the others. Both 5′-amino-5′deoxyadenosine compounds were active against vaccinia virus only. Of the three 3′, 5′-dideoxyadenosines, only one had both cytotoxic and antiviral activity. Most, if not all, seemingly antiviral effects appear to be caused

ISSN:0009-3157    

DOI:10.1159/000237923

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The in vitro activity of netilmicin was compared to gentamicin, tobramycin and amikacin against 461 strains of glucose fermenting and nonfermenting bacteria. The minimum inhibitory concentrations of netilmicin, gentamicin and tobramycin against the majority of Enterobacteriaceae, Staphylococcus and Streptococcus were quite similar. Gentamicin, however, was approximately fourfold more active against strains of S. marcescens. Amikacin was the most effective antibiotic against strains of fermenting and nonfermenting bacilli resistant to at least one aminoglycoside. Many gentamicin-resistant species of nonfermenting bacilli, however, remain highly resistant to all four aminoglycosides tested.

ISSN:0009-3157    

DOI:10.1159/000237924

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The in vitro antibacterial activity of HR-756 was compared to cefoxitin and cefuroxime. 122 multiresistant clinical isolates including Enterobacteriaceae (104) and P. aeruginosa (18), which present particular problems in antibiotic chemotherapy, were selected for study. HR-756 inhibited all the strains of S. marcescens, P. mirabilis and indole-positive Proteus spp. at a concentration of 1,3 and 12 μg/ml, respectively; β-lactamase-producing strains were also susceptible. 90% of K. pneumoniae and more than half of the Enterobacter and P. aeruginosa were inhibited from the drug at a concentration of 16 μg/ml. Cefoxitin and cefuroxime were less active than HR-756. Cefoxitin was more effective against S. marcescens and P. mirabilis while the same was the case with cefuroxime against K. pneumoniae strains. The greater efficiency of HR-756 over cefoxitin and cefuroxime against these multiply resistant isolates seems to be due not only to its indifference to the β-lactamases but also to its easier penetrability into the bacterial c

ISSN:0009-3157    

DOI:10.1159/000237925

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

589 isolates of anaerobic bacteria, including 127 isolates of Bacteroides fragilis, were tested against 23 antimicrobial agents. At their usually achievable serum levels, carbenicillin, ticarcillin, mezlocillin and piperacillin; cefoxitin, minocycline, doxycycline, clindamycin, chloramphenicol and rifampin were effective against more than 80% of B. fragilis isolates, At usual therapeutic doses, penicillin (PEN), ampicillin (AMP), cyclacillin (CYC), cephalothin (CT), cefazolin (CZ), cephradine (CPD), cefamandole (CMD), cefaclor (CCL), cefuroxime (CRX), spectinomycin (SPT), tetracycline (TET), ethambutol (EMB) and isoniazid (INH) were ineffective against B. fragilis. However, high and clinically tolerated doses of PEN, CMD and SPT inhibited more than 80% of B. fragilis isolates, but AMP, CYC, CT, CZ, CPD, CCL and CRX, TET, EMB and INH remained totally ineffective against B. fragilis. The therapeutic merits of these antibiotics are discussed.

ISSN:0009-3157    

DOI:10.1159/000237926

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

The minimal inhibitory concentration for tobramycin and gentamicin against 488 clinical isolates of Enterobacteriaceae, Staphylococcus aureus and Pseudomonas spp. were obtained on three different solid media. The results obtained on Antibiotic Sensitivity Medium AB Biodisk (PDM) were markedly different from the results obtained on Mueller-Hinton (MH) and Diagnostic Sensitivity Test Agar Oxoid (DST). It was shown that tobramycin was significantly disfavored relative to gentamicin by PDM agar compared to MH and DST agar.

ISSN:0009-3157    

DOI:10.1159/000237927

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Bacterial growth kinetic experiments have been performed to study the potentiating effect of trimethoprim (TMP) and TMP derivatives on the antibacterial action of sulfonamides (SA). The TMP derivatives showed different inhibitory effects when used alone. Derivatives with decreased inhibitory activity excerted ‘bactericidal’ effects only at high concentrations. A rather fast development of bacteria with lower sensitivity against these derivatives has also been observed. In the combined action with SA, however, the same maximal ‘kill’ rate was observed for TMP derivatives as tetroxoprim or derivative IV (table I) at low concentrations of these inhibitors. Under the experimental conditions there is no significant difference between the studied TMP derivatives and various SA in the combined

ISSN:0009-3157    

DOI:10.1159/000237928

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

A randomized controlled study was undertaken to compare the effectiveness of three umbilical cord treatment regimens in controlling neonatal bacterial colonization. The regimens studied included daily application of castile soap, triple dye and silver sulfadiazine. The triple dye and silver sulfadiazine regimens inhibited bacterial colonization. Staphylococcal colonization was inhibited most effectively by triple dye treatment. Group B streptococcal colonization was equally inhibited by triple dye and silver sulfadiazine. Silver sulfadiazine was more effective in controlling colonization with gram-negative microorganisms.

ISSN:0009-3157    

DOI:10.1159/000237929

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

28 patients with aerobic (7), anaerobic (7), and mixed (14) infections were treated with intravenous piperacillin for an average duration of 14 days. All bacterial isolates tested in this study were susceptible to piperacillin ≤ 128 μg/ml. 27 patients were treated with 20 g of piperacillin/day in four divided doses. 1 patient with renal failure received only 8 g/day. 26 patients were treated with piperacillin and two with Staphylococcus aureus infection received gentamicin in addition. The peak serum levels were 266 μg/ml at 1 h and the trough 16 μg/ml at 5 h. In all, 26 patients (93%) were ‘cured’, one had ‘recurrence’, and one ‘failed’. Adverse effects were pruritus in two patients, transient elevation of LDH in one, and transient eosinophilia in another. In our preliminary study, piperacillin was found to be safe and effective in the treatment of cli

ISSN:0009-3157    

DOI:10.1159/000237930

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

20 patients with serious infections were treated with cefazolin and tobramycin for 9–64 days. Minimal inhibitory concentration (MIC) values and minimal bactericidal concentration (MBC) values were determined for each of the 112 clinical bacterial isolates. The median cefazolin MIC/MBC was 1.56/12.5 μg/ml, and the median tobramycin MIC/MBC was 6.25/25.0 μg/ml for all organisms studied. Median cefazolin doses of 49.0 mg/kg/day gave median peak/trough serum levels of 43.0/11.0 μg/ml. Median tobramycin doses of 4.3 mg/kg/day gave median peak/trough serum levels of 5.0/1.4 μg/ml. Checkerboard studies revealed synergy with 65% of strains. Bacteriologic and clinical success was obtained in 17 of 20 pat

ISSN:0009-3157    

DOI:10.1159/000237931

出版商:S. Karger AG    

年代:1980

数据来源: Karger