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Biomedical subjects

R E Buck

Publications and source records attributed to R E Buck.

17 recordsLinked to original sources
PubMed1987

BMY 28100, a new oral cephalosporin.

BMY 28100, a new oral cephalosporin with a (Z)-propenyl side chain at the 3 position and a p-hydroxyphenylglycyl substituent at the 7 position, was evaluated in comparison with cefaclor and cephalexin and, when appropriate, ampicillin and vancomycin. In vitro, BMY 28100 was more active than the reference cephalosporins against streptococci, Staphylococcus aureus, Staphylococcus epidermidis, Listeria monocytogenes, Haemophilus influenzae, Propionibacterium acnes, Clostridium perfringens, and Clostridium difficile. BMY 28100 was comparable to cefaclor and more active than cephalexin against Staphylococcus saprophyticus and ampicillin-susceptible strains of Branhamella catarrhalis; but against ampicillin-resistant strains of B. catarrhalis, BMY 28100 was comparable to cephalexin and more active than cefaclor. Against Neisseria gonorrhoeae, BMY 28100 was comparable to cephalexin, but less active than cefaclor. Members of the family Enterobacteriaceae overall were equally susceptible to BMY 28100 and cefaclor but were less susceptible to cephalexin. In human serum, BMY 28100 was 45% protein bound. After an oral dose to mice, 82% of the drug was recovered in urine. The oral therapeutic efficacy of BMY 28100 in systemically infected mice reflected its activity in vitro.

Animals↗
PubMed1985

Comparison of a new cephalosporin, BMY 28142, with other broad-spectrum beta-lactam antibiotics.

BMY 28142, a new broad-spectrum semisynthetic cephalosporin, was evaluated in vitro and in vivo in comparison with ceftazidime, cefotaxime, moxalactam, and cefoperazone. The activity of BMY 28142 compared favorably with the activities of the other compounds against both Pseudomonas aeruginosa and Staphylococcus aureus and was somewhat greater against members of the family Enterobacteriaceae. The influence of inoculum size on MICs of BMY 28142 was small for most of the isolates tested, except Enterobacter species. With Enterobacter strains, a marked inoculum effect was found with all of the compounds, and the effect was more pronounced in broth than agar. Still, MICs of BMY 28142 in broth did not exceed 16 micrograms/ml. Of 37 Enterobacteriaceae strains resistant to one or more of the comparison beta-lactams, none were resistant, at a low inoculum size (10(4) CFU), to BMY 28142, compared with 3 for moxalactam, 18 for ceftazidime, 23 for cefotaxime, and 34 for cefoperazone; at an inoculum size of 10(6) CFU, the number of resistant strains was 12, 17, 25, 34, and 37, respectively. Binding to human serum proteins approximated 19%. Recovery of 73% of the drug in mouse urine indicated good bioavailability. The in vitro profile was sustained in vivo by the results obtained with experimental infections in mice. BMY 28142 was as effective as ceftazidime against systemic infection with P. aeruginosa and as effective as cefotaxime against systemic infection with S. aureus. Overall, infections with 18 of 20 strains representing nine genera were responsive to BMY 28142 at doses equivalent to or lower than those of the most effective of the comparison compounds.

Animals↗
PubMed1985

Antibacterial activity of phosphanilic acid, alone and in combination with trimethoprim.

We explored the antibacterial activity of phosphanilic acid (P), an analog of sulfanilic acid, alone and in combination with trimethoprim (T; TP, 1:5) with sulfamethoxazole (S) and co-trimoxazole, the combination of this sulfonamide with trimethoprim (TS, 1:5) as the reference. P resembled S in spectrum but, in addition, had significant activity against Pseudomonas aeruginosa. The overall frequency and degree of synergism with TP were lower than with co-trimoxazole. P, like S, was strongly affected by changes in inoculum size and was not bactericidal. P was well absorbed parenterally but not orally in mice. Despite low (but prolonged) blood levels, P, given orally to mice, was effective in treating infections caused by P. aeruginosa. However, against most experimental infections the therapeutic effectiveness of P, as well as that of TP, administered either intramuscularly or orally was unimpressive. Based on in vivo data, the therapeutic application of P or TP would appear to be limited.

4-Aminobenzoic Acid↗
PubMed1984

Empedopeptin (BMY-28117), a new depsipeptide antibiotic. I. Production, isolation and properties.

Empedopeptin is a new antibiotic produced by empedobacter haloabium nov. sp. (ATCC 31962). It is a water-soluble depsipeptide antibiotic containing eight amino acid residues and a C14-fatty acid moiety in the molecule. Although structurally unrelated, empedopeptin and vancomycin have similar antimicrobial spectra against aerobic and anaerobic Gram-positive bacteria including antibiotic-resistant strains. Empedopeptin is highly active in vivo in mice against systemic infections of Staphylococcus aureus, Streptococcus pyogenes and Clostridium perfringens. Empedopeptin is not absorbed orally.

Animals↗
PubMed1979

Bactericidal activity of cefadroxil, cephalexin, and cephradine in an in vitro pharmacokinetic model.

Cefadroxil (Duricef, Mead Johnson and Company), resembles cephalexin and cephradine in spectrum of antibacterial activity but differs in human pharmacokinetic properties. Whether the latter are likely to affect activity in vivo was assessed by determining bactericidal activity against clinical isolates under conditions simulating the variation of drug concentration in the blood stream after an oral dose of 500 mg to adults. In this kinetic model, cefadroxil was more active than cephalexin or cephradine against Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, Proteus mirabilis, Haemophilus influenzae and one of two strains of Escherichia coli. The other strain of E. coli was virtually unaffected by the cephalosporins. S. pyogenes was equally susceptible to all three cephalosporins. Analysis of the results suggest that the pharmocokinetic properties of an antibiotic affect its activity in the blood stream, provided the susceptibility of the infecting organism is concentration-dependent within the range of drug concentration occurring in serum.

Adult↗
PubMed1979

Comparative bactericidal effect of ceforanide (BL-S 786) and five other cephalosporins in an in vitro pharmacokinetic model.

The bactericidal activity of ceforanide was compared, in an in vitro kinetic model, with that of five other cephalosproins: cephalothin, cefazolin, cefamandole, cefuroxime, and cefoxitin. Cultures of various pathogens in 95% human serum were incubated for 12 hours in the presence of the cephalosporins whose concentrations were modified periodically-by addition of a concentrated solution of drug or dilution with unmedicated serum-in order to simulate the variation of antibiotic concentration in human blood after one-gram intramuscular dose. One Gram-positive strain and six Gram-negative strains were used. Bactericidal activity was assessed by monitoring changes in the number of colony-forming units. Tests showed that against Klebsiella pneumoniae, ceforanide was the most active of the six cephalosporins. Proteus mirabilis was more susceptible to ceforanide and cefuroxime than to the other compounds; Enterobacter cloacae to ceforanide, cefuroxime, and cefamandole; Escherichia coli to ceforanide, cefuroxime, cefamandole, and cefazolin. The number of viable cells of Staphylococcus aureus was reduced below detectable levels by all cephalosporins except cefoxitin. On the other hand, Providencia stuartii was virtually unaffected by all of the cephalosporins except cefoxitin.

Bacteria↗
PubMed1977

Cefadroxil, a new broad-spectrum cephalosporin.

Cefadroxil is a new semisynthetic cephalosporin with a broad antibacterial spectrum and a high chemotherapeutic potential when administered orally. The inhibitory activity of this compound was similar to that of cephalexin and cephradine when tested against 602 clinical isolates on Mueller-Hinton medium. In the oral treatment of experimental infections of mice, cefadroxil was more effective than cephalexin against Streptococcus pyogenes, and comparably effective against Streptococcus pneumoniae, Staphylococcus aureus, and several gram-negative species. Administered orally to mice, at doses ranging from 25 to 100 mg/kg, cefadroxil attained peak concentrations in the blood similar to those of cephalexin. At a dose of 200 mg/kg, however, higher peak levels were noted with cefadroxil than with cephalexin. In regard to other properties which were investigated, the behavior of cefadroxil compared favorably to that of cephalexin.

Animals↗
PubMed1976

Laboratory evaluation of BL-S786, a cephalosporin with broad-spectrum antibacterial activity.

Biological and physicochemical properties of BL-S786 were compared with those of cephalothin, cephaloridine, and cefazolin. With few exceptions, BL-S786 was more active than the reference compounds against major gram-negative pathogenic species and its antibacterial spectrum was broader than that of cephalosporins currently available for clinical use. Although BL-S786 was generally less active than the control cephalosporins against gram-positive pathogens, it inhibited their growth at concentrations that should readily be achieved in humans after standard parenteral dosage. Streptococcus faecalis, a species relatively unsusceptible to cephalosporins in general, was an exception. BL-S786 was an effective bactericidal agent for strains of various gram-negative organisms. After intramuscular administration to mice, BL-S786 achieved high concentrations in blood, and its biological half-life was longer than that of the other three cephalosporins.

Animals↗
PubMed1975

BL-S 640, a cephalosporin with a broad spectrum of antibacterial activity: properties in vitro.

BL-S 640 was evaluated in vitro by comparison with cephalothin, cephaloridine, cefazolin, and cephalexin. The new compound was more active than the control cephalosporins against most major gram-negative and some gram-positive species. Moreover, its antibacterial spectrum included strains of Enterobacter, Proteus morganii, P. rettgeri, and Providencia stuartii, species generally resistant to the other cephalosporins. BL-S 640 was an effective bactericidal agent for strains of various species of Enterobacteriaceae. In human plasma, the compound was 58% protein bound.

Bacteria↗
PubMed1972

7-(Alpha-(1-methyl-4-pyridinothio)-acetamido) cephalosporanic acid.

7-[alpha-(1-Methyl-4-pyridiniothio)-acetamido] cephalosporanic acid, referred to herein as BL-S 217, is a new broad-spectrum semisynthetic cephalosporin that offers several advantages over cephalothin. A comparison of the activity in vitro of these antibiotics indicates that BL-S 217 is about eightfold more effective against Streptococcus pyogenes and Diplococcus pneumoniae. Against gram-negative bacteria, BL-S 217 possesses a broader antibacterial spectrum than cephalothin, particularly against members of the Enterobacteriaceae family; e.g., BL-S 217 inhibited over 20% more strains of both Escherichia coli and Klebsiella than cephalothin and also showed some advantage in tests against Salmonella and Enterobacter. Overall, of 208 strains of Enterobacteriaceae tested, 172 were susceptible to BL-S 217 compared to 149 for cephalothin. BL-S 217 was less bound to human serum proteins than cephalothin and gave higher peak blood levels in mice after intramuscular administration. The LD(50) of BL-S 217 in mice after subcutaneous administration was in excess of 4,000 mg/kg. When administered by the same route to mice experimentally infected with cephalothin-sensitive bacterial strains, this new cephalosporin was 20 times more effective than cephalothin in S. pyogenes and D. pneumoniae infections and 3 to 4 times more efficacious in an E. coli infection. Its therapeutic efficacy was comparable to that of cephalothin in infections produced by strains of Staphylococcus aureus, Klebsiella pneumoniae, and Proteus mirabilis.

Acetamides↗