Biomedical subjects
Publications and source records attributed to J C Pechère.
A beta-lactamase isolated from a strain of Bacteroides fragilis subsp. fragilis possessed hydrolytic activity toward cefotaxime. This antibiotic was degraded to a lower extent than was cephalothin, cephaloridine, and cefamandole, whereas cefoxitin remained unaffected by the enzyme. Kinetic parameters Vmax and Km for cefotaxime were calculated at 0.172 mumol/min and 1.1 X 10(-2) mM, respectively.
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Forty-two patients were followed up after 44 renal transplantations in an effort to evaluate possible benefits from the following protocol: systematic microbiologic and clinical surveillance, early and aggressive research for the cause of suspected infections, refusal to use prophylactic antibiotherapy, and selection of treatment according to the established cause of the infection. During 18,030 days of follow-up 124 infections were recorded, of which 110 were bacterial, 11 viral and 3 protozoal. Eighty originated in the urinary tract, 17 in skin wounds and 10 in the lower respiratory tract. Septicemia occurred three times, and one death due to infection was recorded. In the treatment of bacterial infections patients received antibiotics for 2486 days. Ampicillin (given for 816 days) and "minor" drugs such as sulfonamides and urinary antiseptics (given for 1036 days) were used 74.5% of the time, whereas gentamicin was used only 2.6% of the time (64 days). Combined antibacterial therapy was needed 1.2% of the time (29 days). A restrictive policy regarding anti-biotherapy seems to be beneficial to renal transplant recipients.
The disc diffusion technique was evaluated with 178 strains of anaerobes and four cephalosporins (cephalothin, cefamandole, cefazolin and cefoxitin). Good correlation in results was found in comparison with the agar dilution technique (p less than 0.001) with the exception of cefamandole and cefazolin against anaerobic cocci (p greater than 0.05). Choosing a breakpoint of 8 microgram/ml for distinguishing susceptible and resistant strains, we determined corresponding incubation, the rate of error is less than 1% for false susceptible and less than 5% for false resistant. However, some strains of anaerobic cocci required a 48 hour incubation period for allowing visible growth. Moreover, a great deal (60.5%) of overlapping zone diameters made interpretation of disc diffusion test difficult among Bacteroides fragilis strains classed as susceptible, intermediate and resistant occuring with cefoxitin. The results have shown that the cephalothin disk will not accurately predict susceptibility of B. fragilis to cefoxitin.
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The pharmacokinetics of intravenously administered sisomicin were studied in 33 patients with normal renal function and different degrees of renal impairment. In all patients, the serum disappearance of sisomicin, once distribution equilibrium had been achieved, followed first-order kinetics and percentage of hourly loss from serum decreased proportionally with decreasing renal function. Half-lives averaged 2.06 h in normal subjects (endogenous creatinine clearance greater than 80 ml/min per 1.73 m(2)) and reached 35.3 h in a virtually anephric subject. Linear relationships were defined between sisomicin serum half-life and the reciprocal of the endogenous creatinine clearance and serum creatinine concentration. The latter relationship indicates that the half-life of sisomicin may be approximated as twice the serum creatinine concentration and may be used for dosage adjustment in renal-impaired patients. Prediction of the extent of sisomicin removal by hemodialysis may be made from the relationship between the dialyzate of sisomicin and that of creatinine and blood urea nitrogen. Dosage schedules and methods of administration compatible with the pharmacokinetic properties of the antibiotic are finally proposed.
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Explore the source record for details and available documents.
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Newer beta-lactam antibiotics, notably the third generation cephalosporins (3 GC) have been designed for providing high intrinsic potency against a large variety of microorganisms. Bacterial resistance can occur however, and nowadays, clinicians are concerned by novel situations where even most recently developed compounds can be ineffective. A first situation is generated by bacteria which produce great amounts of chromosomal cephalosporinase. The resistance emerges during therapy, in hospital isolates which are classified as susceptible with conventional susceptibility testing. The prevalence of 3 GC resistance among these gram-negative rods with inducible beta-lactamase seems to increase in some institutions but the significance of susceptibility testing in this regard is doubtful. It is probably more important to note that the prevalence of gram-negative rods with inducible beta-lactamases remains stable. A second problem arose with the abrupt development of plasmid mediated beta-lactamases markedly active against 3 GC. This resistance is underestimated because some strains fall into susceptibility range of 3 GC as determined by MICs or inhibition zone sizes. These extended spectrum enzymes are now distributed over four continents and represent a growing threat.
A multicenter, double-blind, randomized, two-arm study was conducted to compare two dosage regimens of roxithromycin--150 mg b.i.d. and 300 mg once daily--in 1588 patients with infectious disease, 1573 of whom were evaluable for safety and 1391 for efficacy. There were no significant differences in demographic or disease characteristics at presentation. Treatment duration averaged 10 days in both groups. Clinical response rates (% satisfactory response) were similar in both arms (b.i.d. versus once daily, respectively): upper respiratory tract, 95.3 and 95.0; lower respiratory tract, 93.1 and 93.6; and skin and soft tissue, 93.1 and 93.0. Bacteriologic response was also similar. The overall incidences of adverse events were 8.5% for daily dosing and 7.2% for b.i.d. dosing, but there was a slightly greater frequency of gastrointestinal events (p less than 0.03) was observed with the once-daily regimen. Thus roxithromycin 300 mg once daily can be recommended as an effective and well-tolerated alternative to the conventional b.i.d. regimen.
Fluoroquinolones are active against a wide variety of bacteria. The antibacterial spectra of fluoroquinolones encompass staphylococci, Bacillus species, and Corynebacterium species implicated in infections of the immunocompromised host; Enterobacteriaceae; most intestinal pathogens; and many gram-negative organisms commonly causing nosocomial infections. Haemophilus influenzae, Haemophilus ducreyi, Neisseria gonorrhoeae, Neisseria meningitidis, and Branhamella catarrhalis are highly susceptible to this class of drugs. Because of their ability to penetrate into phagocytes, fluoroquinolones have been tested against intracellular pathogens: Legionella species, Rickettsia conorii, Rickettsia rickettsii, and Brucella melitensis are very sensitive; Chlamydia trachomatis and the mycoplasmas are borderline; and some antimycobacterial activities deserve further investigation. Species that are generally resistant include Pseudomonas maltophilia, Pseudomonas cepacia, Pseudomonas pseudomallei, Alcaligenes species, Nocardia species, Bordetella bronchiseptica, and most anaerobes.
This study was carried out to determine patient perceptions of respiratory tract infections and attitudes to taking antibiotics, thus helping doctors to have a better understanding of their patients and their requirements. Telephone interviews were conducted in the UK, Belgium, France, Italy, Spain and Turkey using standardized questionnaires directed at patients who had taken an antibiotic or given one to their child for a respiratory tract infection within the previous 12 months. Approximately 200 working adults (< or = 55 years), 200 elderly adults (> 55 years) and 200 mothers of children (< 12 years) from each country were contacted; in total, 3610 subjects. Pressure on GPs to prescribe antibiotics was highlighted by over 50% of interviewees' believing that they should be prescribed for most respiratory tract infections. Although interviewees were positive about antibiotics, with over 75% judging them to be effective and to speed recovery, some ambivalence was shown. Most patients waited 2-3 days before consulting their doctor and over 80% of respondents expected symptoms to improve after 3 days' treatment. This provided a natural watershed for compliance, with most defaulters stopping after 3 days because they felt better. Second only to fewer side-effects, patients ranked shorter and more convenient dosage alongside efficacy as the improvements most sought in antibiotic therapy. In conclusion, patients regarded antibiotics as important in the treatment of respiratory tract infections, with interest shown in short-course, once-daily therapy. Doctors, however, need to reassure patients that short courses will eradicate infections and have minimal adverse effects on the immune system.