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Biomedical subjects

H C Neu

Publications and source records attributed to H C Neu.

At least 379 records · Page 21Linked to original sources
PubMed1978

Cefuroxime, a beta-lactamase-resistant cephalosporin with a broad spectrum of gram-positive and -negative activity.

The in vitro activity of cefuroxime, a cephalosporin antibiotic, was investigated against 604 isolates and compared with the activity of other beta-lactam compounds. Cefuroxime had activity comparable to that of other cephalosporins, including cefamandole and cefoxitin, against streptococcal and staphylococcal species; most streptococci were inhibited by 0.1 mug or less per ml, and staphylococci were inhibited by 1.6 mug or less per ml. Enterococci were relatively resistant. Cefuroxime inhibited beta-lactamase-producing Neisseria gonorrhoeae and Haemophilus influenzae. Cefuroxime had excellent activity against members of the Enterobacteriaceae; 83% of beta-lactamase-producing Escherichea coli, 100% of Salmonella, 100% of Klebsiella, 90% of Proteus mirabilis, 95% of Citrobacter, 56% of Enterobacter, and 58% of Shigella were inhibited by 12.5 mug/ml. Cefuroxime had activity comparable to that of cefamandole and cefoxitin; it inhibited isolates of E. coli and Klebsiella resistant to cefamandole and inhibited Enterobacter and Citrobacter resistant to cefoxitin. Many isolates of Serratia, some indole-positive strains of Proteus, and Bacteroides fragilis were resistant to cefuroxime. Resistance of cefuroxime to hydrolysis by beta-lactamases played a major role in its activity against both gram-positive and gram-negative organisms.

Amidohydrolases↗
PubMed1978

Synergy of azlocillin and mezlocillin combined with aminoglycoside antibiotics and cephalosporins.

Synergistic activity between both azlocillin and mezlocillin and aminoglycosides or cefazolin could be demonstrated by checkerboard dilution, isobologram, and killing curve techniques. Azlocillin and mezlocillin combined with gentamicin, netilmicin, or amikacin were synergistic against Escherichia coli, Klebsiella, Citrobacter, Enterobacter, Serratia, and indole-positive Proteus. Synergy was observed with isolates that were susceptible or resistant to azlocillin or mezlocillin. Synergy was seen most often when azlocillin or mezlocillin were combined with amikacin, gentamicin, or netilmicin against Pseudomonas aeruginosa. The combination of mezlocillin and an aminoglycoside produced synergy more often than did carbenicillin plus an aminoglycoside. No antagonism was seen when aminoglycoside antibiotics were combined with azlocillin or mezlocillin. Cefazolin was synergistic against Pseudomonas, Providencia, P. mirabilis, indole-positive Proteus, Citrobacter, Klebsiella, and Escherichia coli, when combined with azlocillin or mezlocillin. However, the combination of either agent with cefazolin was antagonistic when tested against selected indole-positive Proteus and Enterobacter isolates.

Aminoglycosides↗
PubMed1978

Azlocillin and mezlocillin: new ureido penicillins.

The activity of azlocillin and mezlocillin, new semisynthetic ureido penicillins, was investigated and compared with that of other known beta-lactam antibiotics. At a concentration of 25 mug/ml, azlocillin inhibited 74% of Enterobacter, 97% of Proteus mirabilis, 64% of Citrobacter, 91% of Pseudomonas aeruginosa, and 82% of Bacteroides strains tested. Mezlocillin inhibited 86% of Shigella, 96% of Enterobacter, 80% of indole-positive Proteus, 88% of Bacteroides, and 63% of Pseudomonas strains tested. Azlocillin was more active against Pseudomonas than was ticarcillin, carbenicillin, or mezlocillin. Mezlocillin was more active than carbenicillin and ampicillin against Escherichia coli, Klebsiella, Enterobacter, Citrobacter, Acinetobacter, Serratia, and Bacteroides. Azlocillin and mezlocillin were less active than cefazolin against beta-lactamase-producing E. coli and Klebsiella strains but more active than cefazolin against Enterobacter, indole-positive Proteus, Acinetobacter, Citrobacter, and Serratia strains. Both compounds showed activity equivalent to that of cefoxitin against Bacteroides isolates. Both agents were destroyed by many of the beta-lactamases from gram-negative organisms.

Bacteria↗
PubMed1978

In vitro activity and beta-lactamase stability of BL-S786 compared with those of other cephalosporins.

In vitro activity of BL-S786, a new parenterally semisynthetic cephalosporin, was investigated against 570 bacterial isolates. BL-S786 inhibited most Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Salmonella. It inhibited some Enterobacter and indole-positive Proteus, but it was less active against these later species than was cefamandole, cefuroxime, or cefoxitin. It was not active against Serratia marcescens, Pseudomonas aeruginosa, or Bacteroides fragilis. BL-S786 was the least active new cephalosporin tested against staphylococci and was less active than cephalothin against streptococcal species. The activity of BL-S786 was not altered by the type of assay medium nor by 50% serum. The size of the test inoculum altered the minimal inhibitory and bactericidal concentrations for inhibition of some organisms, particularly those with Richmond type I beta-lactamases. BL-S786 was not hydrolyzed by the R-factor-mediated, Richmond type III beta-lactamase, but it was hydrolyzed by type I beta-lactamases.

Amidohydrolases↗
PubMed1978

Activity of 5-episisomicin compared with that of other aminoglycosides.

5-Episisomicin, a semisynthetic aminoglycoside, has been shown to inhibit many members of the Enterobacteriaceae, Pseudomonas aeruginosa, and Staphylococcus aureus. At a concentration of 3.1 mug/ml, more than 90% of Escherichia coli, Klebsiella pneumoniae, Enterobacter, Citrobacter, indole-positive Proteus, and Providencia were inhibited. 5-Episisomicin had activity against S. aureus, E. coli, Klebsiella, Enterobacter, and Citrobacter similar to gentamicin and netilmicin. It had activity similar to amikacin and netilmicin against many gentamicin-resistant bacteria. The activity of 5-episisomicin was greatest at an alkaline pH and in medium of low magnesium content. Synergy of 5-episisomicin and carbenicillin was found to occur most often against Pseudomonas.

Aminoglycosides↗
PubMed1978

beta-lactamase stability of HR 756, a novel cephalosporin, compared to that of cefuroxime and cefoxitin.

The stability to beta-lactamase hydrolysis of HR 756, a new cephalosporin antibiotic, was compared to the beta-lactamase stability of cefoxitin and cefuroxime. HR 756, cefoxitin, and cefuroxime were not hydrolyzed by Richmond type I, III, IV, and V beta-lactamases. Antibacterial activity of HR 756 correlated well with resistance to beta-lactamase hydrolysis except against Pseudomonas aeruginosa. HR 756, cefoxitin, and cefuroxime inhibited type I beta-lactamases, but not type III, IV, or V enzymes. HR 756 was the most active inhibitor.

Cephalosporins↗
PubMed1978

Clavulanic acid, a novel inhibitor of beta-lactamases.

Clavulanic acid, Z-(2R,5R)-3-(beta-hydroxyethylidene)-7-oxo-4-oxa-1-azabicyclo-[3,2,0] heptane-2-carboxylic acid, has been shown to be an effective inhibitor of the beta-lactamases of the Richmond types II, III, IV, and V. Inhibition is a time-dependent reaction and is irreversible. Clavulanic acid had poor antibacterial activity against Staphylococcus aureus, Enterobacteriaceae, and Pseudomonas aeruginosa, with minimal inhibitory levels greater than 25 mug/ml. It did inhibit the majority of Neisseria gonorrhoeae at 0.1 mug/ml and Haemophilus influenzae at 6.3 mug/ml. Clavulanic acid acted synergistically with penicillins and cephalosporins to inhibit beta-lactamase-producing S. aureus and Enterobacteriaceae. Clavulanic acid combined with ampicillin inhibited beta-lactamase-producing N. gonorrhoeae, H. influenzae, Escherichia coli, Salmonella typhi, and Shigella sonnei.

Ampicillin↗
PubMed1978

A sulfone beta-lactam compound which acts as a beta-lactamase inhibitor.

CP-45,899 [3,3-dimethyl-7-oxo-4-thia-1-azabicyclo(3,2,0)heptane-2-carboxylic acid, 4,4-dioxide [2S-(2alpha,5alpha)]] has low intrinsic activity against most Gram-positive cocci, Enterobacteriaceae and Pseudomonas. It inhibits Neisseria at concentrations of 0.1 approximately 6.2 microgram/ml. The combination of CP-45,899 and ampicillin inhibited Staphylococcus aureus and Enterobacteriaceae resistant to ampicillin by virtue of beta-lactamase activity. Combination of CP-45,899 and cephalothin was synergistic less often, and CP-45,899 did not act synergistically with carbenicillin or ticarcillin against Pseudomonas resistant to these agents. CP-45,899 acted synergistically with ampicillin against Bacteroides. Synergy of CP-45,899 and ampicillin was demonstrated at varying concentrations suggesting that it may significantly enlarge the antibacterial activity of ampicillin against resistant bacteria.

Anti-Bacterial Agents↗
PubMed1978

The comparative synergistic activity of amikacin, gentamicin, netilmicin and azlocillin, mezlocillin, carbenicillin and ticarcillin against Serratia marcescens.

The synergistic activities of netilmicin, gentamicin and amikacin combined with carbenicillin, ticarcillin, azlocillin and mezlocillin were investigated against 32 Serratia marcescens isolates. Synergy could be demonstrated by killing curve technique, isobologram plots as susceptibility data with any of the aminoglycosides and penicillins combinations. No antagonism was shown with any of the combinations. The majority of the isolates were resistant to the aminoglycosides and penicillins. Combination of either ureido-penicillin or carbenicillin with gentamicin or netilmicin did not reduce the MIC values to levels achievable in serum but did reduce the MIC levels of both agents to those achievable in urine. The combination of ureido-penicillins or carbenicillin and ticarcillin with amikacin reduced the inhibitory levels of all isolates to levels achievable in both serum and urine.

Amikacin↗
PubMed1978

1-N HAPA gentamicin B, a new aminoglycoside active against gentamicin resistant isolates--activity compared to other aminoglycosides.

1-N HAPA gentamicin B is a new aminoglycoside active against most Enterobacteriaceae, Pseudomonas aeruginosa and Staphylococcus aureus. Among 504 clinical isolates at a concentration of 12.5 microgram/ml all Staph. aureus, Escherichia coli, Klebsiella, Enterobacter, Proteus rettgeri, Providencia and 78% of Pseudomonas, 86% of Proteus morganii were inhibited. Like other aminoglycosides, the activity was greatest at an alkaline ph and reduced by high cations concentrations. 1-N HAPA gentamicin B was equal in activity to amikacin against both gentamicin-sensitive and resistant isolates. It inhibited bacteria containing many of the aminoglycoside inactivating enzymes. When combined with carbenicillin it inhibited in a synergistic manner many Gram-negative bacteria, particularly Pseudomonas and Serratia.

Aminoglycosides↗
PubMed1978

Gentamicin in 1978.

For a decade gentamicin has been used extensively because of its antimicrobial efficacy and the relatively low prevalence of clinical toxicity. Recently the more frequent appearance of resistant organisms, reports of increased nephrotoxicity and ototoxicity, and the development of newer aminoglycoside antibiotics have raised doubts about the continued use of this agent. This paper reassesses the role of gentamicin. It is clear that an appreciation of the pharmacokinetics and the clinical use of gentamicin as well as an understanding of the patterns of toxicity in animals and humans can lead to more efficient treatment with this antimicrobial agent. Despite ample competition from a number of newer aminoglycoside antibiotics, gentamicin will probably continue to be used widely in the near future.

Amikacin↗
PubMed1978

What should the clinician expect from the microbiology laboratory?

Many physicians do not know what they should expect from the microbiology laboratoy. What physicians need from the microbiology laboratory varies according to type of patient and type of physician. The laboratory should provide information that will affect clinical management guidelines for obtaining specimens, microbial identification, antimicrobial susceptibilities, rapid collection of material, and reporting of data and educational updating. Data are needed to establish how the physician responds to microbiologic reports.

Bacterial Infections↗
PubMed1978

How is the medical student being trained in microbiology and infections?

Reduction in curriculum time and shifts in interests of microbiology and epidemiology departments have altered the nature of the exposure of medical students to clinical problems of microbiology and infectious diseases. Major objectives of training in microbiology and infectious diseases are poorly met because of the large mass of material the student needs to assimilate. Students graduate from medical school using antimicrobial agents as a substitute for diagnostic acumen, without an understanding of how microbiologic laboratories should be used. Methods to improve this situation should be studied.

Education, Medical↗
PubMed1978

Acute interstitial nephritis associated with carbenicillin therapy.

Although acute interstitial nephritis has been documented during therapy with many antibiotics of the penicillin class, it has not previously been reported in association with carbenicillin therapy. We report here the case of a patient who developed the characteristic clinical features of this form of injury while receiving prolonged large doses of carbenicillin. Histologic examination confirmed the presence of a striking interstitial nephritis. Carbenicillin should be considered a potential cause of renal damage in patients who develop rash, eosinophilia, and microscopic hematuria in association with deterioration of renal function.

Acute Disease↗
PubMed1977

The pharmacology of newer aminoglycosides, with a consideration of the application to clinical situations.

This has been an overview of the pharmacology of tobramycin, a new potent aminoglycoside, particularly active against Pseudomonas aeruginosa. Close attention must be given to the administration of this compound, and to the administration of all aminoglycosides, if one is to achieve adequate serum and tissue concentrations without provoking a toxic renal or otic reaction. Differences in methods and dosage of administration depending upon age, status of renal function, and route of administration are discussed. The basic principles reviewed can be applied to all the agents in this class.

Aminoglycosides↗