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Biomedical subjects

M F Michel

Publications and source records attributed to M F Michel.

At least 127 records · Page 7Linked to original sources

Therapeutic activities of cefazolin, cefotaxime, and ceftazidime against experimentally induced Klebsiella pneumoniae pneumonia in rats.

The efficacies of several dosage schedules of cefazolin, cefotaxime, and ceftazidime, started 12 or 36 h after infection, were examined in experimental pneumonia caused by Klebsiella pneumoniae in rats. The therapeutic activities of the cephalosporins were compared with the antibacterial activities in vitro and the serum concentration curves. The course of experimental pneumonia was rapid and characterized by tissue necrosis. Response to antimicrobial treatment was evaluated with respect to mortality and numbers of bacteria in lung (left lobe), blood, and pleural fluid. When antibiotic treatment was started early, i.e., 12 h after bacterial inoculation, cefotaxime and ceftazidime were equally effective and superior to cefazolin. Eleven doses of 10 mg of cefotaxime or ceftazidime per kg or 11 doses of 60 mg of cefazolin per kg were required to improve the survival rate. With a delay in administration to 36 h after inoculation, the efficacy of the cephalosporins decreased markedly. In the three dosages tested, cefazolin was ineffective. Survival improved with the administration of nine doses of 60 mg of cefotaxime per kg or nine doses of 10 mg of ceftazidime per kg. These results are not in accordance with the ratio of in vitro activities of cefotaxime and ceftazidime or the serum concentration curves.

Animals↗

Detection of Neisseria gonorrhoeae antigen by a solid-phase enzyme immunoassay.

The Gonozyme test (Abbott Laboratories) is a new enzyme immunoassay for detecting Neisseria gonorrhoeae antigens in specimens from the urethra in men and the endocervix in women. To evaluate the usefulness of the assay 249 patients were investigated. The results obtained with the immunoassay were compared with those of culture and microscopy of Gram-stained smears. The sensitivity and specificity of the test were high in men with urethritis and acceptable in different groups of women. As the sensitivity of the Gonozyme test was much higher than that of microscopy for endocervical specimens it might be useful as a rapid screening test for the detection of gonorrhoea in women.

Antigens, Bacterial↗

Efficacy of ampicillin therapy in experimental listeriosis in mice with impaired T-cell-mediated immune response.

The importance of intact host defense mechanisms for successful antimicrobial therapy was investigated via a comparison of the activities of ampicillin against experimental Listeria monocytogenes infections in normal mice and congenitally athymic (nude) mice. Nude mice were used for these experiments because recovery from infection with this organism depends on development of cellular immunity induced specifically by a T-cell-mediated reaction. When infections ampicillin per mouse (32 doses of 25 mg each), which is twenty times the dose required for a cure of infections in normal mice (8 doses of 5 mg each), would not cure infections in nude mice. With a reduction in inoculum to 10(5) colony-forming units, cures were obtained with a total ampicillin dose of 800 mg (32 doses of 25 mg each), but not with 400 mg (16 doses of 25 mg each). These studies show clearly that the efficacy of ampicillin against infections with L. monocytogenes is dependent upon intact host defense mechanisms.

Ampicillin↗

Relationship of the interval between infections and the similarity of gonococcal strains in recurrent gonorrhoea.

Paired gonococcal isolates from 38 patients with recurrent episodes of gonorrhoea at varying intervals were examined for similarity by means of gonococcal auxotyping and susceptibility to antibiotics. A different gonococcal strain was the cause of the second infection in 53% of the patients. Longer intervals between infections were significantly associated with greater numbers of dissimilar strains as a cause of the second infection. The same strain was usually found in infections occurring within 60 days of each other whereas different strains were more likely to cause infections occurring more than 60 days apart. The isolates causing the second infection were significantly more susceptible to penicillin.

Anti-Bacterial Agents↗

Gonorrhea in Rotterdam caused by penicillinase-producing gonococci.

Recently the prevalence of strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) in the Netherlands has increased. A study of demographic and clinical data from patients with gonorrhoea due to PPNG strains, and of the biological characteristics of the strains isolated in Rotterdam, show that Asian strains of PPNG seem at present to be endemic in the Netherlands. Spectinomycin was found to be effective in the treatment of patients with gonorrhoeea due to PPNG strains.

Female↗

Antibiotic sensitivities of gonococci isolated in Rotterdam and results of treatment with cefuroxime.

In a study of the efficacy of cefuroxime in the treatment of 278 cases of acute gonorrhoea (including rectal and pharyngeal infections and infections due to penicillinase-producing Neisseria gonorrhoeae), high cure rates were found for both male (98.8%) and female patients (98.6%). Disadvantages of this treatment are its high cost and the relatively high proportion of patients who develop postgonococcal urethritis.

Anti-Bacterial Agents↗