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Biomedical subjects

M F Michel

Publications and source records attributed to M F Michel.

At least 73 records · Page 4Linked to original sources
PubMed1987

Diagnosis of invasive candidiasis in patients with and without signs of immune deficiency: a comparison of six detection methods in human serum.

Visceral candidiasis in 56 patients, 39 of whom were thought to be immune deficient, was investigated using three serological detection methods--whole cell agglutination, haemagglutination, and counterimmunoelectrophoresis for antibodies; two determinations of circulating antigens--haemagglutination inhibition and latex agglutination; and determination of the arabinitol:creatinine ratio. Of the 39 patients with suspected immune deficiency, 13 had confirmed invasive candidiasis and 26 were colonised; of those without signs of immune deficiency, 10 patients also had invasive candidiasis and seven were colonised. Twenty three patients with invasive candidiasis were analysed in total. For suspected immune deficient patients the best discrimination between visceral candidiasis and colonisation was obtained by combining the results of haemagglutination inhibition and arabinitol:creatinine ratio. For patients without signs of immune deficiency the best discrimination between invasive candidiasis and colonisation was achieved with counterimmunoelectrophoresis. The results of the serological tests confirmed the classification on clinical grounds of those with and without immune deficiency.

Agglutination Tests↗
PubMed1987

Sexually communicable micro-organisms in human semen samples to be used for artificial insemination by donor.

Two hundred and thirty seven semen samples from 10 institutes for artificial insemination by donor (AID) in Belgium and the Netherlands were tested for the presence of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, herpes simplex virus, and cytomegalovirus. The incidence of these micro-organisms in the semen samples was 0%, 6.3%, 4.6%, 35.9%, 0%, and 0.4% respectively, and 47% of all samples were infected with one or more of the micro-organisms. As the ejaculates from which the samples had been taken had already been, or would be, used for AID, the exclusion of microbiological contamination with sexually communicable micro-organisms before insemination is indicated.

Chlamydia trachomatis↗
PubMed1987

Trends in gonococcal resistance to antibiotics in Rotterdam, The Netherlands, 1975-86.

The incidence of resistance of Neisseria gonorrhoeae to penicillin and tetracycline was periodically monitored during 1975-86. The incidence of resistance to penicillin (minimum inhibitory concentration (MIC) of more than 1.28 mg/l) of non-PPNG strains remained low (less than 2.5%). The incidence of penicillinase producing N gonorrhoeae (PPNG) strains decreased after a peak of 14% in 1982 to a mean of 8% in more recent years. After a gradual increase, the incidence of tetracycline resistant (MIC of more than 1.28 mg/l) strains has remained stable at around 20% during the past five years. This indicates that a continuing increase in incidence of resistance was not observed in this outpatient clinic.

Humans↗
PubMed1987

Tobramycin in patients with cystic fibrosis. Adjustment in dosing interval for effective treatment.

The efficacy of the dosing regimen of tobramycin was investigated in 28 patients with cystic fibrosis who had an acute exacerbation of chronic pulmonary infection with Pseudomonas aeruginosa. The initial dose of tobramycin was 3.3 mg/kg of body weight three times daily (ie, 10 mg/kg/day). A highly significant relationship was found between the serum concentration of tobramycin before the dose and the change in the forced expiratory volume in one second (FEV1), both measured on the tenth day of treatment (rs = 0.75; p less than 0.001). In nine of the 16 patients who had a six-hour serum concentration of 1 mg/L or less on the tenth day of treatment, the eight-hour dosing interval of tobramycin was shortened to achieve a serum concentration of tobramycin of about 1 mg/L before the dose. In the other seven patients, the dosage of tobramycin was not changed. On the 20th day, seven of the nine patients in whom the dosing interval was shortened exhibited an increase in FEV1 of 20 percent or more. Such an increase was observed only in one of the seven patients in whom the dosing interval was not reduced (p less than 0.05). We conclude that individualizing the dosage of tobramycin in patients with cystic fibrosis results in a better clinical outcome.

Acute Disease↗
PubMed1987

[Is juvenile seborrheic dermatitis a candidiasis? Studies of a possible link with microbial infections].

Infantile seborrheic dermatitis (ISD), a disease occurring in the first months of life, is an erythematosquamous skin disease of unknown origin. This article presents results of microbial studies in 20 patients with ISD. Isolation of candida in a high percentage may indicate a primary role of this micro-organism in the etiology of this disease. It is striking that this disease often starts after disturbing the microbial colonization of the intestinal tract. Often ISD develops during the transition of breastfeeding to humanized cow milk.

Bottle Feeding↗
PubMed1986

Evaluation of roxithromycin in the treatment of non-gonococcal urethritis in males.

One-hundred and fifty-two male patients suffering from non-gonococcal urethritis were treated with an oral dosage of 300 mg roxithromycin daily for seven days. Chlamydia trachomatis was isolated from the urethra in 53 patients (35%), and Ureaplasma urealyticum in 42 patients (28%). After treatment, 49 (92%) of the 53 patients with positive Chlamydia trachomatis cultures and 34 (81%) of the 42 patients with positive Ureaplasma urealyticum cultures had negative cultures at follow-up. A clinical cure was observed in 137 patients (90%). Ten patients (7%) showed side effects consisting of nausea, sensation of distended abdomen, headache and fatigue. Seventy-eight male patients suffering from nongonococcal urethritis were treated with an oral dosage of 2 X 150mg roxithromycin daily for seven days. Chlamydia trachomatis was isolated from the urethra in 22 patients (28%), and Ureaplasma urealyticum in 30 patients (38%). After treatment, all of the 22 patients with formerly positive Chlamydia trachomatis cultures and 23 (77%) of the 30 patients with formerly positive Ureaplasma urealyticum cultures were negative at follow-up. A clinical cure was observed in 70 patients (90%). Three patients (4%) showed side-effects consisting of nausea and headache. It is concluded that roxithromycin is a good alternative to tetracycline and erythromycin in the treatment of non-gonococcal urethritis in males.

Anti-Bacterial Agents↗
PubMed1986

Treatment of uncomplicated gonococcal urethritis in men with two dosages of ciprofloxacin.

One hundred and sixty-four male patients suffering from urethral gonorrhoea were treated in an open randomised trial with either 250 mg (n = 85) or 500 mg (n = 79) ciprofloxacin administered in one tablet. Cure rates in both groups were 100%. Postgonococcal urethritis was observed in 31 of 85 (36%) patients in the first group, and in 21 of 79 patients (27%) in the second group. Side-effects were minor, occurring in four patients in the 250 mg group (4.7%) and in seven in the 500 mg group (8.9%). The side-effects consisted of nausea, diarrhoea and headache. Ciprofloxacin would appear to be a very effective drug in the treatment of urethral gonorrhoea in males.

Administration, Oral↗
PubMed1986

In vitro activity of the two new 4-quinolones A56619 and A56620 against Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum and Gardnerella vaginalis.

The in vitro activity of tetracycline, ciprofloxacin and two recently developed 1-aryl-fluoroquinolones, A56610 and A56620, was tested against 65 beta-lactamase-negative and 35 beta-lactamase-positive Neisseria gonorrhoeae strains, 12 Chlamydia trachomatis, 50 Mycoplasma hominis, 28 Ureaplasma urealyticum and 50 Gardnerella vaginalis strains. In the case of Chlamydia trachomatis and Mycoplasma hominis both the MIC and the MBC were determined. The MIC90 of ciprofloxacin for Neisseria gonorrhoeae was 0.008 microgram/ml and of A56619 and A56620 less than or equal to 0.03 microgram/ml. No difference was observed between the activity against beta-lactamase-negative and beta-lactamase-positive strains. The MIC90 values of of ciprofloxacin and A56620 for Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum were identical, the values being 2 micrograms/ml, 1 micrograms/ml and 4 micrograms/ml respectively. The MIC90 of A56619 for Chlamydia trachomatis and Ureaplasma urealyticum was 0.5 micrograms/ml and 1 microgram/ml respectively. The MBC90 values of the three quinolones for Chlamydia trachomatis and Mycoplasma hominis were less than or equal to 2 micrograms/ml. The activity of the quinolones against Gardnerella vaginalis was rather low, the MIC90 being greater than or equal to 4 micrograms/ml. It is concluded that A56619 and A56620 might be useful for single-dose therapy of gonococcal infections.

Anti-Bacterial Agents↗
PubMed1986

Treatment of uncomplicated urogenital gonorrhoea in women with a single dose of enoxacin.

One hundred and twenty-three female patients suffering from uncomplicated urogenital gonorrhoea were treated in a double blind randomised trial with either 200 mg enoxacin (one capsule of 200 mg, one of placebo) or 400 mg enoxacin (two capsules of 200 mg). The cure rate in the 46 evaluable patients in the 400 mg group was 100%, and in the 40 evaluable patients in the 200 mg group 98.7%. Minor side effects such as nausea, headache and skin rash occurred in three of 109 evaluable patients (2.8%). The minimum inhibitory concentration of enoxacin for the Neisseria gonorrhoeae strains isolated varied between 0.03 and 0.12 mcg/ml. Enoxacin would seem to be a very effective drug in the treatment of uncomplicated urogenital gonorrhoea in female patients.

Administration, Oral↗
PubMed1986

Distinguishing complicated from uncomplicated bacteremia caused by Staphylococcus aureus: the value of "new" and "old" serological tests.

Antibody responses to staphylococcal alpha-toxin, cell wall teichoic acid, and cell wall peptidoglycan were measured in 259 serum samples from 74 consecutive patients with Staphylococcus aureus bacteremia. All patients with complicated bacteremia were seropositive in at least one of three tests, and 18 (72%) of 25 were positive in two or three assays; six (75%) of eight patients with endocarditis were positive for all three tests. In contrast, 15 (75%) of 20 patients with uncomplicated bacteremia were positive in only one or none of the tests. These differences in antibody response patterns were statistically significant (chi 2 = 18.33, P less than .001). Patients with complicated bacteremia had peak antibody titers that were significantly higher than those of patients with uncomplicated bacteremia. The assay for antibody to alpha-toxin was as sensitive as the assays for antibody to cell wall antigens but had less specificity for complicated bacteremia. The clinical severity of the bacteremia did not correlate with a complicated vs. uncomplicated nature of the infection but was predictive of early death due to staphylococcemia. The calculated predictive values suggest that the serology of S. aureus bacteremia may be clinically valuable when multiple tests are performed in paired serum samples.

Antibodies, Bacterial↗
PubMed1986

The efficacy of the combination of Timentin and tobramycin in the treatment of patients with bacteraemia.

Twenty-eight patients with bacteraemia were treated with Timentin, a combination of ticarcillin and clavulanic acid, and tobramycin. According to a simple physiological classification scheme 20 patients were moderately and eight severely ill. Clinical cure was achieved in 15 of 20 moderately ill and in four of eight severely ill patients. The nine therapeutic failures were due to non-removable foreign material (2 cases), abscesses that were not effectively evacuated (5 cases), urolithiasis (1 case), and decubitus ulcer (1 case). One of these cases was complicated by infection with a Klebsiella strain with Timentin and tobramycin MICs of 64 mg/l. Thirteen of 31 bacterial isolates from blood were resistant to greater than or equal to 128 mg/l of ticarcillin of which 11 were susceptible to less than or equal to 64 mg/l of Timentin. The addition of Timentin to tobramycin offered a better coverage in vitro than ticarcillin combined with tobramycin against the strains isolated from the blood of the patients included in this study.

Adult↗
PubMed1986

Cell-bound and extracellular autolytic activity of a tolerant and a nontolerant Staphylococcus aureus strain exposed to methicillin.

Cell-bound and extracellular autolytic activity was studied in a tolerant and a non-tolerant Staphylococcus aureus strain after exposure to low (10 mg/l) and high (80 mg/l) concentrations of methicillin. Tolerance was defined as survival after 24 h of over 2% of the inoculum after exposure to high concentrations of methicillin (greater than or equal to 64 mg/l). The nontolerant strain showed an increased cell-bound autolytic activity after exposure to both low and high concentrations of methicillin. The tolerant strain on the other hand selectively showed a reduced cell-bound autolytic activity after exposure to 80 mg/l of methicillin. In both types of strains extracellular activity was less after exposure to a high concentration of methicillin than after exposure to a low concentration. This phenomenon was caused by the release of an inhibitor of the autolysins under the influence of the high concentration of methicillin.

Autolysis↗
PubMed1986

Effect of liposome-entrapped ampicillin on survival of Listeria monocytogenes in murine peritoneal macrophages.

The effect of liposomal encapsulation of ampicillin on the antibacterial activity against intracellular Listeria monocytogenes was studied by comparing survival of L. monocytogenes within peritoneal mouse macrophages in the presence of free ampicillin alone or in combination with liposome-entrapped ampicillin. In the presence of 50 micrograms of free ampicillin per ml of the incubation medium, intracellular growth of L. monocytogenes was still observed, although less as compared with intracellular growth in the absence of ampicillin. At a concentration of 50 micrograms of free ampicillin plus 100 micrograms of liposome-entrapped ampicillin per ml, 99% of the intracellular bacteria were killed. On the other hand, a concentration of 150 micrograms of free ampicillin per ml plus empty liposomes only inhibited intracellular bacterial growth, and the bacteria were not killed. In addition, empty liposomes at a concentration of 1 mumol of lipid per ml had no effect on intracellular bacterial growth. In broth, liposome-entrapped ampicillin at a concentration of 100 micrograms/ml was not bactericidal for L. monocytogenes, indicating that significant leakage of ampicillin from the liposomes with subsequent killing of the bacteria by the free drug did not occur. Therefore, we concluded that liposomal encapsulation of ampicillin results in an increased availability of the antibiotic for the intracellular bacteria.

Ampicillin↗
PubMed1986

Continuous versus intermittent administration of ceftazidime in experimental Klebsiella pneumoniae pneumonia in normal and leukopenic rats.

Experimental Klebsiella pneumoniae pneumonia was used to study the influence of cyclophosphamide-induced leukopenia on the relative therapeutic efficacy of continuous and intermittent (6-h intervals) administration of ceftazidime. The antimicrobial response was evaluated with respect to the calculated daily dose that protected 50% of the animals from death (PD50) until 16 days after the termination of a 4-day treatment. When ceftazidime was administered intermittently to leukopenic rats, the PD50 was 24.37 mg/kg per day, 70 times (P less than 0.001) the PD50 of 0.35 mg/kg per day for normal rats. Continuous administration of ceftazidime to leukopenic rats resulted in a PD50 of 1.52 mg/kg per day, four times (P less than 0.001) the PD50 of 0.36 mg/kg per day for normal rats. Continuous administration of ceftazidime in daily doses that protected 100% of normal and leukopenic rats from death resulted in serum levels of 0.06 and 0.38 micrograms/ml, respectively, whereas the MIC for the infecting K. pneumoniae strain was 0.2 micrograms of ceftazidime per ml. The effect of the duration of ceftazidime treatment by continuous infusion on the therapeutic efficacy in relation to the persistence of leukopenia was then investigated in leukopenic rats. The administration of 3.75 mg of ceftazidime/kg per day for 4 days protected all leukopenic rats from death, provided the circulating leukocytes returned at the end of antibiotic treatment. When leukopenia persisted for 8 days this ceftazidime treatment schedule resulted in the mortality of rats (P less than 0.05). However, when ceftazidime treatment was continued for 8 days, until the return of the leukocytes, there was no significant mortality (P greater than 0.05).

Animals↗