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Biomedical subjects

E Bernard

Publications and source records attributed to E Bernard.

At least 19 recordsLinked to original sources
PubMed1992

Application of DNA amplification to pneumocystosis: presence of serum Pneumocystis carinii DNA during human and experimentally induced Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia is a leading cause of morbidity and mortality in patients with the acquired immunodeficiency syndrome (AIDS). Much remains unknown about the basic biology of P. carinii and studies of this infection have been hampered by the lack of cultivation methods. We developed a sensitive and specific assay for P. carinii by utilizing DNA amplification of the P. carinii dihydrofolate reductase (DHFR) gene. By this method, P. carinii DNA was detected in the lungs of rats with experimentally induced P. carinii pneumonia 2 wk before the onset of histopathological changes. DNA amplification analysis of serum demonstrated that by 10 wk of corticosteroid treatment, 12 of 12 (100%) infected rats had circulating DHFR DNA. P. carinii DHFR DNA also was detected in the serum of patients with AIDS and active P. carinii pneumonia (12 of 14 sera collected prospectively). Patients with advanced AIDS but without a history of P. carinii pneumonia were negative by this assay (0 of 6 sera examined). Serum polymerase chain reaction may facilitate investigations into the natural history and epidemiology of P. carinii infection, provide insight into the pathogenesis of parasite dissemination, and offer a useful, noninvasive diagnostic test for the detection of human pneumocystosis.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Effect of subinhibitory concentrations of cefamandole and cefuroxime on adherence of Staphylococcus aureus and Staphylococcus epidermidis to polystyrene culture plates.

The ability of cefamandole and cefuroxime to inhibit adherence of staphylococci to polystyrene culture plates was tested in an in vitro assay using eight strains each of Staphylococcus aureus and Staphylococcus epidermidis. The results indicated that subinhibitory concentrations of cefamandole and cefuroxime altered the adherence ability of both staphylococcal species, inhibition of adherence being more marked in the presence of cefamandole. It may be important to consider antiadherence properties in association with bactericidal activity when selecting agents for antibiotic prophylaxis.

Bacterial Adhesion↗
PubMed1992

Efficacy of subinhibitory concentration of pefloxacin in preventing experimental Staphylococcus aureus foreign body infection in mice.

Adhesion is the first step leading to colonization and infection of a foreign body (FBI). To assess the ability of a subinhibitory concentration (subMIC) of pefloxacin (P) to prevent such infection, an experimental model was developed in Swiss albino mice. Subcuts of polyurethane catheters (Vygon) were placed in the peritoneal cavity of animals and 24 hours later, different inocula of an adherent strain of Staphylococcus aureus (SA) (MIC of P:0.8 mg/l) were injected i.p. Unexposed SA served as controls. Two days later the removed catheters, blood and spleen specimens were quantitatively cultured for bacterial content and identity. Infection was defined as more than 10 CFU/ml of SA recovered. Significant protection of mice, with lower dissemination, was found with inoculum sizes of 10(5) and 10(6). These results suggest that subMICs of P may confer protection against foreign body infection.

Animals↗
PubMed1992

[Histopathologic features of opportunistic infections of the small intestine in acquired immunodeficiency syndrome].

The frequency of the opportunistic infections of the duodenum in AIDS patients was determined by way of histologic study in 207 patients between January 1987 and June 1991. All cases had serial paraffin sections, run through HES, PAS, Giemsa, Brown-Brenn, and Zieh-Neelsen stains, and 20 cases had in addition cytologic and electron microscopic study. 63 patients had opportunistic infections (10 cryptosporidiosis and 2 isosporiasis; 12 mycobacterial enteritis; 15 CMV enteritis; 7 candidosis; 7 intestinal microsporidiosis confirmed by electron microscopic examination; 12 Giardiasis; 3 duodenal leishmaniasis; 1 intestinal cryptococcosis). Multiple concurrent infections were noted in 6 cases. A mild to severe villous atrophy was observed in 28 cases, associated with opportunistic infection. A patchy distribution of pathogen agent was noted in 34 cases, and 37 cases were associated with oesophagal candidosis. This study points out the value of histologic examination of intestinal biopsy for the diagnosis of systemic infections as well as of unusual parasitosis, and the necessity for multiple endoscopic biopsies because of the frequent patchy distribution of pathogens.

AIDS-Related Opportunistic Infections↗
PubMed1992

[Fungal myocarditis in acquired immunodeficiency syndrome].

The authors report 8 cases of fungal myocarditis discovered at autopsy of a series of 118 patients with AIDS. The cardiac disease was symptomatic and responsible for death in 2 cases. Antemortem diagnosis of fungal infection was made on examination of bronchioloalveolar lavage, the cerebrospinal fluid or gastrointestinal biopsy. The demonstration of intramyocardial pathogens was postmortem in all cases. The organism was Candida albicans in 3 cases, Cryptococcus neoformans in 3 cases, and Aspergillus fumigatus in 2 cases. The lesions were not confined to the heart; multi-visceral fungal involvement was diagnosed at autopsy in all cases. Cryptococcal and Candida myocarditis have already been described in most autopsy series in AIDS, but Aspergillus myocarditis is very rare. These fungal myocarditis are usually clinically latent or masked by neurological or respiratory symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Analysis of risk factors for surgical wound infections following vascular surgery.

Although surgical wound infections (SWI) following implantation of prosthetic devices can be catastrophic and often require removal of the prosthesis, few studies have identified risk factors for these infections. We conducted a prospective multicenter study to identify risk factors for SWI. Of 561 vascular surgery patients enrolled in the study, 23 (4.1%) developed SWI. Multivariate analysis using logistic regression analyses identified surgery on lower extremities, delayed surgery, diabetes mellitus, past history of vascular surgery, and short antimicrobial prophylaxis (three doses of cefamandole) as independent risk factors for SWI. Consequences of SWI were serious; two (9%) died, 11 (48%) required reoperation, and five (22%) had their prosthesis removed. A risk index was developed using the independent risk factors for SWI identified by logistic regression analyses. When no risk factors were present, no SWI was observed (0 of 100), and the rate of SWI increased from 2.5% when one risk factor was present to 53.8% (7 of 13) when greater than or equal to 4 risk factors were present.

Cefamandole↗
PubMed1991

[Bactericide activity of cefadroxil comparated with amoxicillin-clavulanic acid, cefaclor and josamycin].

Betalactamase-producing organisms are responsible for an increasing number of ENT and lower respiratory tract infections. Or cephalosporins and the combination of amoxicillin with the beta-lactamase inhibitor clavulanic acid are alternatives to ampicillin therapy. The killing activity of cefadroxil on the organisms most often responsible for ENT and respiratory infections was evaluated in vitro using a viable bacteria count method, comparatively with cefaclor, josamycin, and amoxicillin-clavulanic acid. Killing activity was found to be time-dependent for all the antimicrobial agents studied. Cefadroxil exhibited the same bactericidal effect on Streptococcus pyogenes and S. pneumoniae than the other agents. Haemophilus influenzae and an increasing number of Pneumococcus strains were resistant to josamycin which is therefore not appropriate for first-line therapy. As compared with amoxicillin and amoxicillin-clavulanic acid, cefadroxil was less active on H. influenzae and more active on Staphylococcus aureus. Production of beta-lactamase failed to influence the killing activity of cefadroxil. These bacteriologic data, together with results of pharmacologic studies (long half-life and good penetration within tissues) can explain the clinical successes obtained with cefadroxil in ENT and lower respiratory tract infections.

Amoxicillin↗
PubMed1991

[Bactericidal effect of cefadroxil, amoxicillin alone or in combination with clavulanic acid in sera of healthy volunteers].

Determination of minimal inhibitory concentrations (MICs) provides data on the susceptibility or resistance of a bacteria; however, in susceptible bacteria this parameter is not predictive of effectiveness of the antimicrobial agent. Bactericidal activities of cefadroxil, of amoxicillin, and of the amoxicillin-clavulanic acid combination on bacteria commonly found in ENT and lower respiratory tract disease were studied comparatively. The antibiotics were given by the oral route to six healthy volunteers. With beta-lactamase-producing and non-beta-lactamase-producing strains of Escherichia coli, amoxicillin produced MICs consistent with susceptibility but failed to exhibit a bactericidal effect, whereas cefadroxil was bactericidal. Combination of amoxicillin with an inhibitor did not modify this activity on E. coli and failed to produce a bactericidal effect on Klebsiella pneumoniae similar to that seen with cefadroxil. Amoxicillin with and without clavulanic acid exhibited comparable effectiveness on Streptococcus pyogenes and S. Pneumoniae. The bactericidal effect of cefadroxil on S. pneumoniae was of similar magnitude but shorter duration than that of amoxicillin. Cefadroxil and the amoxicillin-clavulanic acid combination had similar bactericidal effects against Staphylococcus aureus. These antibiotics exhibited a time-dependent effect on Gram positive microorganisms. These pharmacodynamic data, together with measures of bactericidal activity, may be very helpful for selecting the appropriate antibiotic and dosage.

Amoxicillin↗
PubMed1991

[Effect of fibronectin on the adhesion of staphylococci and interaction with pefloxacin's anti-adherence properties].

Fibronectin (Fn) is recognized for its ability to mediate Staphylococcus aureus (SA) adhesion. The number of Fn receptors is dependent on the phase of growth, and type of media. Furthermore, it was of interest to examine SA and Staphylococcus epidermidis (SE) adherence to porcine Fn (IBF 10 ng/ml) immobilized on tissue culture plates. The aim of our study was to examine if removal of FN receptors by growing bacteria in an antibiotic containing medium decreased the ability to adhere and of pefloxacin (P) anti-adhesive properties were medium dependent. As SE usually lack Fn binding capabilities, it seemed of interest to investigate if the effects of subinhibitory concentrations of P were modified by medium or Fn. We found: a) For SA: whether Fn coated onto plastic substrata promoted adherence of strains, P's anti-adhesive properties were saved, non medium or phase of growth dependent. b) For SE: adherence properties were decreased if Fn was coated onto plates. P's anti-adhesive properties were not modified and non medium dependent. The number of Fn receptors on clinical isolates of SA correlates with the invasiveness of the isolates. As P reduced the binding of SA to Fn coated plates, this observation may have important implications for antimicrobial prophylaxis.

Bacterial Adhesion↗
PubMed1991

[Intestinal microsporidiosis. 3 cases in HIV seropositive patients].

Three cases of intestinal microsporidiosis are reported, in acquired immunodeficiency syndrome patients, with a chronic diarrhea. The first case is associated with an intestinal cryptococcosis and with a cytomegalovirus infection and the second case was diagnosed on ileal biopsy specimen. Since the first description of Enterocytozoon bieneusi in 1985. 49 cases of intestinal microsporidiosis are reported in the literature, all in AIDS patients and the frequency of this infection is probably underrated. Prospective studies find it in 6 to 30% of cases. This parasite must be suspected in HIV seropositive patients with clinically chronic unexplained diarrhea or with intestinal atrophy.

Acquired Immunodeficiency Syndrome↗