Search PubMed⌕ Search

Biomedical subjects

H C Neu

Publications and source records attributed to H C Neu.

At least 109 records · Page 6Linked to original sources
PubMed1989

Comparative in vitro activity of a new quinolone, AM-1091.

The in vitro activity of a new quinolone, AM-1091 [7-(3-amino-1-pyrrolidinyl)-8-chloro-1-cyclopropyl-6-fluoro-1,4-dihydro- 4-oxo- 3-quinoline carboxylic acid hydrochloride], was compared with those of ciprofloxacin, ofloxacin, beta-lactams, and gentamicin. AM-1091 inhibited 90% of the isolates of the family Enterobacteriaceae at less than or equal to 0.12 micrograms/ml. For many species AM-1091 was 2-fold more active than ciprofloxacin and 2- to 32-fold more active than ofloxacin. It inhibited Enterobacter, Citrobacter, and Klebsiella species resistant to ceftazidime and gentamicin. Ninety percent of Pseudomonas aeruginosa isolates were inhibited by 0.5 micrograms/ml, so for this species AM-1091 was twofold less active than ciprofloxacin. AM-1091 was more active against Pseudomonas cepacia and Xanthomonas maltophilia, inhibiting isolates resistant to imipenem and gentamicin. Most Haemophilus influenzae, Neisseria gonorrhoeae, Neisseria meningitidis, and Branhamella catarrhalis isolates were inhibited by less than or equal to 0.06 micrograms/ml. The MICs for 90% of Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis isolates were 0.06, 0.06, and 2 micrograms/ml, respectively. AM-1091 inhibited hemolytic streptococci and Streptococcus pneumoniae at 0.25 micrograms/ml and was more active than ciprofloxacin or ofloxacin against gram-positive species. AM-1091 inhibited 90% of the Bacteroides species at 0.5 micrograms/ml. The frequency of spontaneous resistance was less than 10(-10) for most organisms, but resistant strains could be selected by repeated subculturing. Although AM-1091 had lower in vitro activity at pH 5.5 and in the presence of high concentrations of Mg2+, it still inhibited most organisms at </= 0.5 micrograms/ml under these conditions. AM-1091 rapidly killed Escherichia coli and P. aeruginosa and had a prolonged postantibiotic suppressive effect on these bacteria.

4-Quinolones↗
PubMed1989

In vitro activity of S-ofloxacin.

S-Ofloxacin, the optically active form of ofloxacin, was twice as active as the S,R mixture of ofloxacin against members of the family Enterobacteriaceae, Pseudomonas aeruginosa, and gram-positive species. Of the Enterobacteriaceae, 90% were inhibited by less than or equal to 1 microgram/ml and 90% of Staphylococcus aureus and Streptococcus pyogenes isolates were inhibited by 0.5 microgram/ml. Bacteroides fragilis was inhibited by 4 micrograms/ml. Organisms resistant to ofloxacin were resistant to S-ofloxacin. Like ofloxacin activity, the activity of S-ofloxacin was reduced by Mg2+ and by acid pH. Spontaneous mutational resistance to S-ofloxacin was similar to that to ofloxacin.

Bacteria↗
PubMed1989

In vitro activity of ME1228, a new parenteral cephalosporin.

ME1228 is a new cephalosporin with an iminocarboxymethyl moiety on the acyl side chain and a novel pyridiniumthiomethyl group at position 3 of the bicyclic ring. Its activity was compared with those of ceftazidime, imipenem, piperacillin, and gentamicin. ME1228 inhibited most members of the family Enterobacteriaceae, except for some Enterobacter spp. and Citrobacter freundii, at less than or equal to 0.25 micrograms/ml, and it inhibited gentamicin- and piperacillin-resistant isolates. It had MICs for Pseudomonas aeruginosa between 1 and 32 micrograms/ml, comparable to those of ceftazidime, and it inhibited piperacillin- and gentamicin-resistant isolates. Most group A, B, C, and G streptococci and Streptococcus pneumoniae were inhibited by less than or equal to 0.25 micrograms/ml. Enterococci and listeriae were resistant (MICs, 64 to 128 micrograms/ml). The MICs for staphylococci were 4 to 8 micrograms/ml, and methicillin-resistant Staphylococcus aureus was resistant. There was a minimal inoculum effect and no effect of the medium. ME1228 was not hydrolyzed by TEM-1, TEM-2, SHV-1, and S. aureus plasmid beta-lactamases and was stable against hydrolysis by Richmond-Sykes type 1a, 1c, 1d, and IV chromosomal beta-lactamases. It was hydrolyzed by TEM-3 and Xanthomonas maltophilia beta-lactamases. Overall, ME1228 had activity comparable or superior to that of ceftazidime.

Anti-Bacterial Agents↗
PubMed1989

Oligonucleotide probe for detection and identification of Campylobacter pylori.

We have developed a novel and practical DNA-RNA hybridization assay for the detection and identification of Campylobacter pylori in the gastric mucosa. This technique utilizes a [32P]ddATP-labeled synthetic oligonucleotide probe complementary to a nucleotide sequence present in C. pylori 16S rRNA. This probe is very sensitive and reacted with all 23 strains of C. pylori tested. It is also highly specific, since there was no cross-reactivity with the heterologous organisms Campylobacter coli, C. fetus subsp. fetus, C. jejuni, and C. laridis or with Escherichia coli. Hybridization of the oligonucleotide probe with C. pylori RNA was completely inhibited by treatment of the membrane filters with RNase but not DNase. Although a gastric mucosa tissue homogenate slightly inhibited the hybridization, as few as 10(4) C. pylori cells could be detected even in the presence of 5 mg of gastric mucosa. Gastric biopsy specimens obtained from patients referred for upper gastrointestinal tract endoscopy were tested for C. pylori infection by direct oligonucleotide hybridization, and the results were compared with those of bacteriological cultures, the urease test, and histological observations. A comparison of the urease test and the oligonucleotide hybridization results showed an excellent correlation between the two methods. The clinical usefulness of this oligonucleotide-RNA hybridization method is discussed.

Campylobacter↗
PubMed1989

The quinolones.

The molecular basis of activity, chemistry, microbiology, and pharmacology of the new fluoroquinolones is reviewed in this article. Areas of clinical use are analyzed with specific reference to efficacy, development of resistance, and potential for toxicity.

4-Quinolones↗
PubMed1988

Cephalosporin antibiotics: molecules that respond to different needs.

Since the introduction of cephalothin in 1964, there has been a large number of cephalosporins synthesized and used clinically. Modification of the beta-acyl side chain has yielded compounds with stability against attack by plasmid and chromosomal beta-lactamases. The presence of methoxy groups at C-7 of the bicyclic cephalosporin nucleus has provided excellent activity against many anaerobic species. Changes in structure have also provided agents with extended half-lives, permitting twice a day dosing or single-dose prophylaxis. Cephalosporins clearly have come of age as agents to meet many different infectious needs.

Cephalosporins↗
PubMed1988

Gastrointestinal histoplasmosis.

Three cases are reported of gastrointestinal histoplasmosis in patients who came from the Caribbean or South America and had lymphoma, acquired immunodeficiency syndrome, and prior local radiation therapy. The patients had small-bowel obstruction with ileal involvement, mucosal erythema, and friability on colonoscopy with colonic involvement and an exophytic rectal mass with rectal involvement. Review of the 77 reported cases of gastrointestinal histoplasmosis shows that this is a clinical subset of disseminated histoplasmosis. With gastrointestinal involvement, pulmonary symptoms are uncommon and gastrointestinal symptoms predominate. Fever is less common than in other forms of dissemination. The most common lesions are a mass or ulcers, which often mimic inflammatory bowel disease or carcinoma. Terminal ileal involvement predominates in one third. The complement fixation test was positive in about three quarters of cases tested, but the skin test is not diagnostically useful. In one quarter of patients there is other evidence of immunosuppression. In the immunosuppressed, gastrointestinal histoplasmosis must be considered, even in a patient from a nonendemic area, who presents with lesions appearing like carcinoma or inflammatory bowel disease. When feasible, endoscopic examination and biopsy with stains and culture for histoplasmosis is recommended for diagnosis. Medical management is recommended, with surgery reserved for acute emergencies or when mandatory for diagnosis.

Adult↗
PubMed1988

In vitro activity of temafloxacin, a new difluoro quinolone antimicrobial agent.

Temafloxacin, a new difluoro quinolone, inhibited the majority of Enterobacteriaceae at less than or equal to 1 microgram/ml. It was 4-8-fold less active than ciprofloxacin and 2-fold less active than ofloxacin. Cefotaxime and imipenem-resistant isolates such as Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Acinetobacter spp. were inhibited. Temafloxacin inhibited Neisseria, Branhamella, and Haemophilus species at less than 0.25 microgram/ml. Methicillin-susceptible and methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis and Clostridium spp. were inhibited at concentrations less or equal to that of ciprofloxacin and ofloxacin.

Anti-Bacterial Agents↗
PubMed1988

Comparative in vitro activity of the new oral macrolide azithromycin.

The in vitro activity of the new oral macrolide azithromycin was compared with that of erythromycin against gram-positive and gram-negative aerobic and anaerobic bacteria. Ninety percent of hemolytic streptococci groups A and B, and Streptococcus pneumoniae were inhibited by 0.5 microgram/ml. Activity of azithromycin was similar to that of erythromycin; erythromycin-resistant staphylococci and streptococci were not inhibited. Azithromycin was more active than erythromycin against Haemophilus influenzae (MIC90 1 microgram/ml) and Neisseria gonorrhoeae. It inhibited Campylobacter spp. and Pasteurella multocida, and had an MIC50 of 8 micrograms/ml for Escherichia coli, Salmonella spp., Shigella spp. and Yersinia enterocolitica compared to an erythromycin value of greater than 64 micrograms/ml.

Azithromycin↗
PubMed1988

Aztreonam: the first monobactam.

There are several areas in which the use of aztreonam seems logical. Infections caused by organisms sensitive to aztreonam that are known to be multiresistant to other agents can be treated directly with aztreonam in single, directed therapy, thus making the use of more toxic agents unnecessary. In types of infection in which both gram positive and gram negative bacteria are present, aztreonam can replace the usual aminoglycoside component of the therapeutic regimen. In settings of mixed infections suspected of being caused by drug-resistant strains of Enterobacteriaceae and/or P. aeruginosa, aztreonam can be combined with an agent active against gram positive organisms or with one active against anaerobes. Aztreonam has proven to be effective, safe therapy for serious and life-threatening infections caused by multiresistant aerobic gram negative bacteria. It should be used in combination with drugs that inhibit gram positive species if the etiology of the infection is not known, particularly in the immunocompromised, neutropenic patient. Doses of 1 g every 8 to 12 hours will be adequate for treatment of infections caused by most Enterobacteriaceae. Whether 2 g doses every 8 hours would be preferred for treatment of systemic Pseudomonas infections remains to be determined. Urinary infections caused by gram negative bacteria can be treated with 500 mg administered IM once or twice daily. The dosage of aztreonam should be adjusted in patients with renal failure. Clearly, aztreonam is a useful addition to the antimicrobial agents available to the physician.

Aztreonam↗
PubMed1988

Imipenem: a new carbapenem antibiotic.

Imipenem is a new carbapenem antibiotic that has an extremely broad spectrum of antibacterial activity. It has been used to treat a variety of serious infections and an increasing volume of literature documents its value in infections due to multiresistant bacteria. This article reviews the antibacterial activity, pharmacology, and clinical uses of imipenem.

Animals↗
PubMed1988

Quinolones: a new class of antimicrobial agents with wide potential uses.

Quinolone antibiotics provide potentially important therapy for many infections that heretofore required extensive hospitalization. Improper use of these agents rapidly can lead to resistance and thereby remove them from the physician's arsenal of antimicrobial compounds. It also is possible that with more extensive use, these drugs will demonstrate adverse reactions that to date are unknown. Attention to how the agents are used can simultaneously avoid the problems of resistance and toxicity.

Anti-Infective Agents↗
PubMed1988

Parasitic infections: therapeutic considerations.

Parasitic infections are a problem even in developed countries. Since the agents used to treat these infections are infrequently used, most physicians are unfamiliar with antiparasitic compounds. The activity, mode of action, and use of antiparasitic agents is reviewed.

Antimalarials↗