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Biomedical subjects

M Simonet

Publications and source records attributed to M Simonet.

At least 55 records · Page 3Linked to original sources
PubMed1990

Comparison of cefpodoxime proxetil with cefaclor in the treatment of sinusitis.

The efficacy and tolerance of cefpodoxime proxetil were compared with those of cefaclor in a multicentre, international, prospective, double-blind, placebo-controlled study in adult outpatients suffering from acute sinusitis. At the end of treatment, cefpodoxime proxetil was more effective than cefaclor, producing complete clinical cure in 84% of cases (102/122) vs 68% of cases (77/114) in the cefaclor group (P = 0.01). The overall clinical efficacy (cure + improvement) was similar in the two groups with 95% (116/122) satisfactory responses in the cefpodoxime proxetil group and 93% (106/114) in the cefaclor group. Bacteriological response was similar with 95% eradication in the cefpodoxime proxetil group (55/58) vs 91% with cefaclor (63/69).

Acute Disease↗
PubMed1990

Electron microscopic evidence for in vivo extracellular localization of Yersinia pseudotuberculosis harboring the pYV plasmid.

Electron microscopic evidence is presented that bacteria harboring the virulence plasmid pYV from Yersinia pseudotuberculosis are localized in extracellular sites during the course of infection in mice, often unambiguously undergoing active replication. Virulent pYV+ bacteria, often seen adherent to platelets, severely restricted granuloma formation, creating necrotic microabscesses poorly populated with inflammatory cells. This contrasts with granulomas produced by pYV- bacteria, which appear to be composed mainly of polymorphonuclear and mononuclear cells. Our results therefore strongly suggest that active replication of pYV+ bacteria predominantly, if not exclusively, occurs in vivo in extracellular sites.

Extracellular Space↗
PubMed1990

Molecular typing of nosocomial isolates of Legionella pneumophila serogroup 3.

In Paris, France, an outbreak of pneumonia due to Legionella pneumophila serogroup 3 was observed in Necker (four cases) and Pitié (six cases) hospitals. Neither the 10 clinical isolates nor 5 tap water isolates from Necker Hospital harbored plasmids. Clinical and environmental serogroup 3 isolates and serogroup 3 reference strain Bloomington 2 were analyzed by chromosomal probe fingerprinting. rRNA, 16S and 23S from Escherichia coli and a randomly cloned 15-kilobase-pair nucleotide sequence from L. pneumophila serogroup 3 were used as probes. All strains tested showed a single pattern after HindIII digestion of DNA and hybridization with the 32P-end-labeled rRNA probe, whereas three patterns were obtained after hybridization with the 32P-labeled 15-kilobase-pair DNA probe. One pattern was given by all clinical and tap water isolates from Necker Hospital, another one was given by all clinical isolates from Pitié Hospital, and a last one was given by reference strain Bloomington 2. Thus, molecular analysis showed that the two hospital outbreaks of legionellosis were unrelated and could link the outbreak in Necker Hospital to contaminated tap water.

Bacterial Typing Techniques↗
PubMed1990

[Activity of cefapirin against bacterial strains isolated from acute otitis media in children].

The antibacterial activity of cefapirin was tested against 210 strains isolated from the auricular exudate of childrens' acute otitis media. For 112 strains of Haemophilus studied (20% secreted a beta-lactamase), the MIC 50 and 90 of cefapirin were 2 and 4 mg/l respectively. Ten strains of Branhamella catarrhalis were tested (9 secreted a beta-lactamase) and the MIC ranged from 0.25 to 4 mg/l. Against Streptococcus pneumoniae, cefapirin has an extremely high activity with MIC 50 and 90 less than 0.06 mg/l. Of the strains of Staphylococcus aureus sensitive to meticillin, one had a MIC less than 0.06 mg/l, and 11 had a MIC = 0.25 mg/l. For 14 strains of Enterobacteriaceae studied, we obtained a MIC 50 of 8 mg/l and a MIC 90 of 32 mg/l. The results show that cefapirin is an antibiotic particularly suitable for the treatment of acute otitis media.

Anti-Bacterial Agents↗
PubMed1990

[Activity of cefuroxime against bacterial strains isolated from acute otitis media].

The acute otitis media is a frequent infantile disease and, in 80% of cases, a bacterial strain can be isolated from the otorrhoea. Haemophilus influenzae and Streptococcus pneumoniae are the two major species isolated from auricular exudate, and represent two thirds of all isolated strains, with the others comprising Staphylococcus aureus, Branhamella catarrhalis, Pseudomonas aeruginosa, Enterobacteriaceae and corynebacteria. The treatment of this disease is based principally on beta-lactams (aminopenicillins, cephalosporins) administered by the oral route. Cefuroxime is a cephalosporin which is absorbed via the digestive tract in the form of cefuroxim-axetil. The activity of this compound was studied against 210 strains isolated from otorrhoea, collected from children who presented an acute otitis media during the first half of 1989. These strains were: 112 strains of H. influenzae, of which 23 produced a beta-lactamase; 21 strains of Streptococcus pneumoniae; 3 strains of Streptococcus pyogenes; 10 strains of Branhamella catarrhalis of which 9 produced a beta-lactamase; 18 strains of S. aureus; 14 strains of Enterobacteriaceae, and 32 strains of corynebacteria. The minimal inhibitory concentration (MIC) of cefuroxime-axetil was measured by dilution in agar. The MICs of cefuroxime against H. influenzae were low and similar (MIC 50 = 1 mg/l; MIC 90 = 1 mg/l) regardless of whether the strain secreted a beta-lactamase. Overall, 90% and 98% of the 210 strains tested here were inhibited by 1 and 4 mg/l of cefuroxime respectively. These results show that the antibacterial spectrum of cefuroxime-axetil appears to be ideally suited to the bacterial strains isolated from acute otitis media.

Cefuroxime↗
PubMed1989

Identification of additional virulence determinants on the pYV plasmid of Yersinia enterocolitica W227.

This paper describes the mutagenesis of the pYV plasmid from Yersinia enterocolitica W22703 (serotype O:9) with Tn2507, a new element generating operon fusions. Analysis of the mutants allowed the identification of an additional Yop protein called Yop20 and the mapping of yop20, yop44, yop48, and lcrV, the gene encoding the V antigen. The last gene appeared to be part of an operon that also may contain yop37 and yop44. At 37 degrees C, mutants affected in this operon grew poorly, irrespective of the presence of Ca2+, or they even died in the presence of Ca2+. This operon is thus involved in the regulation by Ca2+, and we called it car, for Ca2+ regulation. It is presumably the Y. enterocolitica counterpart of the lcrGVH operon of Yersinia pestis. Transcription of yop20 and of the car operon was strongly regulated by temperature and only slightly by calcium. Hence, these genes behaved like the other genes of the yop regulon. Mutants affected in yop20 or in yop48 were markedly less virulent for the desferrioxamine-treated mouse than was the parental strain. Yop20 and Yop48 thus probably are Yersinia virulence factors.

Animals↗
PubMed1989

[Comparison of the in vitro activity of amoxycillin + clavulanic acid and ampicillin + sulbactam combinations against 50 Haemophilus influenzae strains producing beta lactamase].

We compared the ability of two beta lactamase inhibitors, clavulanic acid and sulbactam, to reduce the minimal inhibitory concentrations (MICs) respectively of amoxycillin and ampicillin against fifty strains of Haemophilus influenzae producing a beta lactamase. The reduction of MICs of aminopenicillins was studied using low concentrations of beta lactamase inhibitors (0.125 to 0.5 mg/l). Moreover, the synergic effect of each association was evaluated against a heavy bacterial inoculum (10(8) cfu/ml). The combination of amoxycillin + clavulanic acid was more synergic on these strains than the association of ampicillin + sulbactam.

Amoxicillin↗
PubMed1988

[Bacteriology of acute otitis, in current practice, in 1987. Therapeutic implications].

After presenting the methodology of their study and the structure of their chain of swabs, the authors report the bacteriological results and therapeutic consequences which they imply. In this study, which was conducted in children between the ages of 3 months and 3 years, Haemophilus influenzae was the bacterium most frequently isolated, regardless of the age-group. It was followed by Streptococcus pneumoniae and Staphylococcus aureus. Neither the recurrent nature of the otitis nor the child's life style influenced the predominance of Haemophilus influenzae. 23% of the strains were beta-lactamase producers. The production of beta-lactamase prevented the use of amoxicillin. The increasingly frequent resistance of Streptococcus pneumoniae and the poor sensitivity of Haemophilus influenzae discourage the use of macrolids; the combination of amoxicillin-clavulanic acid obtained a better score with an efficacy of 89%.

Acute Disease↗
PubMed1985

Protection against Yersinia infection induced by non-virulence-plasmid-encoded antigens.

Specific immunity against Yersinia was induced by plasmid-encoded antigens not associated with virulence. Mice were immunised with viable bacteria from a virulence-plasmid-cured strain of Y. pseudotuberculosis. This antigenic stimulation generated specific protection against virulence-plasmid-harbouring strains of Y. pseudotuberculosis and Y. pestis, demonstrating that protection can be generated by organisms lacking plasmid-encoded virulence antigens.

Animals↗
PubMed1984

Growth of Yersinia pseudotuberculosis in mouse spleen despite loss of a virulence plasmid of mol. wt 47 X 10(6).

A highly virulent strain of Yersinia pseudotuberculosis (LD50 c. 10(2) bacteria/mouse) harboured two plasmids with mol. wt of 47 X 10(6) and 61 X 10(6). The role of these plasmids in virulence was studied in mice with derived strains cured of plasmids. It was confirmed that the plasmid of mol. wt 47 X 10(6) played a major function in virulence. This was shown both by the increase of the LD50 and the lower rate of multiplication in the spleen obtained with strains cured of the plasmid of mol. wt 47 X 10(6). The plasmid of mol. wt 61 X 10(6) did not play any role in virulence. This work also demonstrates that the strain cured of the plasmid of mol. wt 47 X 10(6) and the plasmid-free strain were able to multiply in the spleens of infected mice during a 7-day period. This suggests that virulence factors not associated with plasmids are also responsible for the bacterial growth in tissues in vivo.

Animals↗
PubMed1984

Impaired resistance to Listeria monocytogenes in mice chronically exposed to cadmium.

It is shown in this work that resistance to Listeria monocytogenes is greatly impaired in C57BL/6 mice chronically exposed to cadmium (Cd) chloride. Animals received 0.5 mg/kg Cd by an intraperitoneal route three times a week during a 4-week period and were then infected with L. monocytogenes. Susceptibility to this pathogenic bacteria was not due to a defect of the specific immune response, since mice developed normal levels of anti-Listeria T cell-mediated immunity and did not show any impairment of macrophage activation. In fact, bacterial growth in organs was rapid in Cd-exposed mice during the early phase of infection, suggesting an impairment of non-specific defence mechanisms. Experimental data indicate that the susceptibility to L. monocytogenes might be due to a defect of macrophage recruitment in sites of infection during the early phase of the host response.

Animals↗
PubMed1981

[Evaluation of ready-to-use media for blood cultures based on 1580 specimens (author's transl)].

We have compared the performance of two types of manufactured media, by making 1580 blood cultures from 250 hospitalized people with bacteremia. The results showed that, within the limits of this present study, the Bacto Tryptic Soy Broth w/SPS and Bacto Thiol Broth w/SPS (DIFCO) are better than the brain heart broth and Schaedler broth (Hemoline, BioMérieux). There was no difference in the microbial growth rate and the type of isolated bacteria with the two brands of media. The superior results obtained with the used media from Difco, as compared to the ones from BioMérieux, could be due to a difference of sensitivity of these broths.

Bacteriological Techniques↗
PubMed1977

[Topographic diagnosis of urinary infection by determination of fraction 5 of lactate dehydrogenase].

Amongst the various methods suggested for the topographical diagnosis of urinary tract infection, the study of various fractions of lactico-dehydrogenase in the urine would appear to be particularly valuable. Study of 44 subjects with a significant urinary infection, compared with an identical group of subjects free of urinary infection, showed that in those with pyelonephritis fraction 5 was significantly (p less than 0.001) higher than in those with a lower urinary tract infection. However this was valid only in the absence of renal insufficiency. Combined study of immunological techniques (urinary antibodies revealed by immunofluorescence and serum antibodies) shows that these techniques are complementary and make it possible to exactly localise the site of a urinary tract infection. In relation to immunology, enzymology has the advantage of being suitable for use during periods at which bacteriological examination of the urine is negative, and hence is useful in following the influence of treatment.

Adolescent↗
PubMedDate not supplied

Data analysis needs for health sector reform.

This paper addresses the role of information in health policy reform. It recognizes that reform can be based on data, but that there are other influences on health policy. The steps involved in making policy, including problem identification, comparison of solutions, policy adoption, implementation, and amendment, all require information. When information is unavailable for any of these steps, the policy process sometimes proceeds without it. The policy makers must make difficult choices regarding the potential benefit of comprehensive information to the policy outcome versus the potential drawbacks, in terms of time and cost, of seeking the missing information. Different areas where data are needed within health policy are enumerated, as are sources of health policy data, and examples of strategies are given. Finally, three case studies are presented, highlighting the use of information in policy making. The National Epidemiology Board in Thailand commissioned studies by experts on relevant policy topics. It had a substantial impact on changing policies in the areas of AIDS control, iodine deficiency, essential drugs and vaccination. The attempt at decentralizing health administration to the province level in Papua New Guinea is the second example presented. At the time of the evaluation, this effort had not yet attained its objectives of improving the health of the people, nor had it reduced costs or lessened inequity among regions. If this reform had been tested in a pilot project, its problems may have been discovered at an earlier stage of implementation when they would have been easier to correct. The final case concerns the UNICEF child survival interventions during the 1980s. These interventions were chosen based on cost-effectiveness analysis and were successfully implemented. The use of cost-effectiveness analysis in prioritizing interventions is one example of the way in which information can improve policy and health outcomes.

Data Collection↗