Ampicillin, a β-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ...

A total of 1,102 clinical isolates of Gram-negative bacilli was obtained from four hospitals during 1967 and these cultures were tested for sensitivity to ampicillin. Approximately 80% of the strains of Escherichia coli and 90% of the strains of Proteus mirabilis, the two organisms most frequently isolated, were sensitive to ampicillin. Klebsiella-Enterobacter species and Pseudomonas aeruginosa...

Poly(ε-caprolactone) (PCL) electrospun fibers containing ampicillin sodium salt have been produced and twisted into nanofiber yarns. The fiber diameters and crystallinity, the in vitro antimicrobial properties of the yarns, and the in vitro release of ampicillin from yarns containing various ampicillin concentrations are studied. Decreased fiber diameters and reduced diameter variation are obse...

THE absence of direct toxicity is one of the most remarkable properties of the penicillin molecule; that is to say, the penicillin molecule as we know it and as we should use it. If you try hard enough, you can make it toxic by altering it or abusing it, as I shall try to show later. With this reservation, one can say that penicillin G and the main therapeutic derivatives of 6-aminopenicillanic...

Minimum inhibitory and bactericidal concentrations of four antibiotics and their combinations were determined for 38 strains of enterococci by a microtitration tube dilution technique. The drugs were ampicillin, vancomycin, gentamicin, and streptomycin; the combinations were ampicillin-gentamicin, ampicillin-streptomycin, vancomycin-gentamicin, and vancomycin-streptomycin. At achievable serum c...

Strains of Haemophilus influenzae type b sporadically isolated from clinical specimens are ampicillin resistant due to production of a beta-lactamase. This enzyme which inactivates ampicillin and penicillin G is not produced by ampicillin-susceptible strains. Various characteristics of beta-lactamase production and ampicillin resistance of three H. influenzae type b isolates were investigated. ...

The effects of free ampicillin, microencapsulated ampicillin anhydrate (MEAA) and antibiotic-free microspheres on the cell-mediated immune response in Balb/c mice were measured by lymphoproliferation assay, delayed-type hypersensitivity (DTH) and cytokine production. Injection into mice for seven consecutive days with equivalent subcutaneous doses of ampicillin, MEAA or placebo microspheres did...

The properties of donor deoxyribonucleic acid (DNA) from three clinical isolates and its ability to mediate the transformation of competent Rd strains to ampicillin resistance were examined. A quantitative technique for determining the resistance of individual Haemophilus influenzae cells to ampicillin was developed. When this technique was used, sensitive cells failed to tolerate levels of amp...

Aztreonam (SQ 26,776), a new monocyclic beta-lactam agent, was compared with ampicillin, ampicillin plus chloramphenicol, and gentamicin in rabbits with experimental meningitis induced by, respectively, ampicillin-susceptible Haemophilus influenzae, ampicillin-resistant H. influenzae, and Escherichia coli. Aztreonam was also compared with gentamicin in experimentally induced E. coli cerebritis ...

Ampicillin was found to be some tenfold more active than amoxycillin against Enterobacter cloacae. This finding explains the observation that some Ent cloacae strains are sensitive to ampicillin in the disc test but resistant to Augmentin. Ampicillin was also found to be more active than amoxycillin against Citrobacter freundii and Serratia marcescens. In view of these findings, the practice of...