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Biomedical subjects

D M Bailey

Publications and source records attributed to D M Bailey.

At least 73 records · Page 4Linked to original sources
PubMed1985

In vitro and in vivo antibacterial activities of the fluoroquinolone WIN 49375 (amifloxacin).

WIN 49375 (amifloxacin) is a synthetic antibacterial agent of the quinolone class. It is similar in chemical structure to pefloxacin but differs by containing a methylamino, rather than an ethyl, substituent at the 1-N position. The activity of WIN 49375 in vitro was comparable to those of norfloxacin and pefloxacin against Enterobacteriaceae and generally greater than those of tobramycin and cefotaxime. WIN 49375 was more active in vitro than carbenicillin and mezlocillin against Pseudomonas aeruginosa isolates and showed moderate activity against Staphylococcus aureus, with MICs of less than or equal to 2 micrograms/ml. The in vitro activity of WIN 49375 was not markedly affected by the presence of human serum, the size of the bacterial inoculum, or changes in pH between 6 and 8. Against systemic, gram-negative bacterial infections in mice, WIN 49375 was generally less active than cefotaxime but more active than gentamicin. WIN 49548, the major piperazinyl-N-desmethyl metabolite of WIN 49375, was aa effective as the parent drug against experimental infections in mice when given parenterally. When administered orally, however, this metabolite was less potent than WIN 49375. WIN 49375 was highly active by the oral route, with 50% effective doses within two- to threefold of those obtained with parenteral medication.

Animals↗
PubMed1985

Microbicidal activity of octenidine hydrochloride, a new alkanediylbis[pyridine] germicidal agent.

The potential of octenidine hydrochloride (WIN 41464-2) as a topical microbicide was measured both by in vitro death kinetics and reductions in numbers of bacteria on the skin of cynomolgus monkeys. Semilogarithmic survival curves were plotted to measure the microbicidal activity of various concentrations of octenidine against Staphylococcus aureus. The microbicidal activity of octenidine was also determined for Staphylococcus epidermidis, Proteus mirabilis, Streptococcus pyogenes, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, and Candida albicans. Death rates for the same microbial strains were compared with those obtained by using chlorhexidine gluconate. Octenidine concentrations of less than 1.5 microM (0.94 microgram/ml) caused a greater than 99% reduction of each microbial population within 15 min. Staphylococcus epidermidis was the most susceptible of the test organisms, and E. coli and C. albicans were the least susceptible. Octenidine was more active than chlorhexidine against each test strain. Skin-degerming activities of aqueous and formulated octenidine and formulated chlorhexidine were compared in single and multiple applications of these agents to the hand and foot surfaces of monkeys by using a glove-juice extraction procedure to measure the skin microflora. Aqueous octenidine, at a concentration of 0.2 to 1.6% reduced resident microflora populations from 90 to 99.98%, depending on the concentration and number of applications. Octenidine formulated at 2% in a surfactant-based vehicle exhibited significantly better skin-degerming activity than did either a nonmedicated vehicle or the Hibiclens brand of 4% chlorhexidine gluconate.

Administration, Topical↗
PubMed1984

Novel amino-substituted 3-quinolinecarboxylic acid antibacterial agents: synthesis and structure-activity relationships.

A series of novel 3-quinolinecarboxylic acid derivatives have been prepared and their antibacterial activity evaluated. These derivatives are characterized by fluorine attached to the 6-position and substituted amino groups appended to the 1- and 7-positions. Structure-activity relationship studies indicate that antibacterial potency is greatest when the 1-substituent is methylamino and the 7-substituent is either 4-methyl-1-piperazinyl, 16, or 1-piperazinyl, 21. Derivatives 16 and 21, the 1-methylamino analogues of pefloxacin and norfloxacin, respectively, show comparable in vitro and in vivo antibacterial potency to these two known agents. The activity (vs. Escherichia coli Vogel) of 16 (amifloxacin) is the following: in vitro MIC (microgram/mL) = 0.25; in vivo (mice) PD50 (mg/kg) = 1.0 (po), 0.6 (sc).

Anti-Bacterial Agents↗
PubMed1984

Bispyridinamines: a new class of topical antimicrobial agents as inhibitors of dental plaque.

A series of N,N'-polyalkylenebis[4-(substituted-amino)pyridines] has been prepared, and members have been evaluated as potential anti-dental plaque agents. From among the most active members of the series, one compound, N,N'-[1,10-decanediyldi-1(4H)-pyridinyl-4-ylidene]bis(1-octanam ine) dihydrochloride, octenidine, was selected as a candidate for clinical study.

Aminopyridines↗
PubMed1983

Relationship between structure and antiplaque and antimicrobial activities for a series of bispyridines.

A series of bispyridines were examined for their bactericidal activities against in vitro, preformed, pure-culture plaques of selected oral plaque-forming bacteria. The antimicrobial activities of these agents were examined in relation to their molecular configurations. These studies demonstrated that the length of the interpyridine polymethylene group bridge and the length of the alkyl side chain were important determinants of antiplaque and antimicrobial efficacy. The most potent compounds of the bispyridine series were studied to determine the minimal conditions (concentration, duration, and frequency) of treatment required for likely clinical efficacy.

Anti-Bacterial Agents↗
PubMed1980

Activity of quinfamide against natural infections of Entamoeba criceti in hamsters: a new potent agent for intestinal amoebiasis.

A novel tetrahydroquinolinyl ester, quinfamide, administered orally in multiple doses for 3 days had an ED50 of 0.25 mg/kg/day (total dose 0.75 mg/kg) for eradicating Entamoeba criceti in hamsters in several tests. It was significantly more active by direct comparison than 3 commercially available amoebicides and at least as active as 2 other esters of the parent compound, 1-(dichloroacety)-1,2,3,4-tetrahydro-6-quinolinol. After administration of a single dose, ED50 calculations for quinfamide averaged 0.9 mg/kg. Quinfamide was considerably more active than the other tetrahydroquinolinols, diloxanide furoate and teclozan, and it was approximately 1.5 times more active than etofamide; a statistical significance between the latter 2 drugs could be demonstrated in one of 4 tests. Administered prophylactically, quinfamide was shown to protect hamsters from re-infection with E. criceti. It also inhibited propagation of E. histolytica in vitro at a concentration of 20 microgram/ml. No adverse effects were noted in rodents after a single dose as high as 10 g/kg. Daily administration to monkeys of doses up to 500 mg/kg for as long as 37 days produced no pharmacological aberrations during or after medication; haematological studies and urine analyses were normal and no gross or microscopical tissue changes attributable to quinfamide were observed. No toxicity was revealed following acute (2 g/kg) and chronic (500 mg/kg/day x 31 days) administration of the drug to dogs and rats, respectively.

Amebiasis↗
PubMed1979

1-(Dichloroacetyl)-1,2,3,4-tetrahydro-6-quinolinol esters. New potent antiamebic agents.

A series of 1-(dichloroacetyl)-1,2,3,4-tetrahydro-6-quinolinols and certain O-acyl derivatives thereof have been prepared and shown to be potent antiamebic agents in the Entamoeba criceti infected hamster model. Compounds were compared with etichlordifene and diloxamide and one of them, 1-(dichloroacetyl)-6-(2-furoyloxy)-1,2,3,4-tetrahydroquinoline (4), was selected for human trial.

Amebicides↗
PubMed1978

The effects of vestibular stimulation on verbalization in chronic schizophrenics.

An experimental group of seven nonparanoid schizophrenic adults was given eight weeks of sensory-stimulating treatment, while a control group of seven similar subjects was given eight weeks of sedentary activities. Three components of language, in response to 16 questions, were measured pre- and post-treatment: number of words used, speed of response, and relevance of response. Analysis of covariance showed that the post-test scores of the experimental group were better than the post-test scores of the experimental group in relevance of response at the .01 level. These results suggest that eight weeks of sensory-stimulating activities can improve the quality of nonparanoid schizophrenic language, but does not appear to have an effect on the quantity or rate of that language.

Adult↗
PubMed1971

Inhibitory and excitatory effects of sympathomimetic amines on muscle strips from the stomach of the guinea-pig.

1. Responses of muscle strips from the stomach of the guinea-pig have been recorded. Sympathomimetic amines cause inhibitory, motor or biphasic responses.2. The motor components of the responses of the preparations were greatly enhanced by the removal of the mucosal layers.3. The inhibitory responses to isoprenaline, noradrenaline and phenylephrine were antagonized by propranolol or by sotalol. The inhibitory responses to noradrenaline and phenylephrine but not isoprenaline were antagonized by phentolamine. Therefore, both alpha- and beta-adrenoceptors may subserve inhibition.4. The motor responses to noradrenaline and phenylephrine were often potentiated by propranolol or sotalol and were antagonized by phentolamine. Therefore, motor responses to sympathomimetic amines appear to involve alpha-adrenoceptors.5. The responses to sympathomimetic amines and their antagonists were not modified by hyoscine or by tetrodotoxin. It is concluded that the adrenoceptors mediating the responses recorded from these preparations are located on the smooth muscle cells rather than on a nervous pathway.

Anilides↗