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Biomedical subjects

O V Renkonen

Publications and source records attributed to O V Renkonen.

At least 55 records · Page 3Linked to original sources

Trimethoprim resistance of Escherichia coli in outpatients in Finland after ten years' use of plain trimethoprim.

Development of trimethoprim resistance among Escherichia coli collected from urine samples in three areas in Finland was studied in 1978-1984. Three different trends of development of resistance were found: in the Turku area resistance has increased evenly during 1978-1982 from 5.4% to 10.1%, but thereafter a plateau seems to have been reached; in the Helsinki area resistance increased rapidly from 2.9% in 1980 to 11.1% in 1984, possibly due to the spread of a trimethoprim resistance transposon Tn7, which occurred significantly more often among E. coli strains in this area than in the Turku area; in the Rovaniemi area resistance has been at a plateau level, between 3.1 and 5.7%, during the whole study. No clear correlation between the consumption of trimethoprim and the level of resistance was found. The frequency of trimethoprim resistance in E. coli isolated from patients less than 65 years was 5.2% and in those isolated from patients greater than or equal to 65 years 14.7%.

DNA Transposable Elements↗

Antimicrobial activity of bupivacaine and morphine.

Antimicrobial activity of bupivacaine and morphine against 10 microbial strains was studied with an agar dilution method. The strains tested were Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), and one of each of the clinical isolates of Staphylococcus epidermidis (a multiresistant strain), Staphylococcus epidermidis (a sensitive strain), Streptococcus pneumoniae, Streptococcus pyogenes (A), Streptococcus faecalis, Bacillus cereus, and Candida albicans. The antimicrobial effect of bupivacaine was tested at concentrations of 0.5, 1.25, 2.5, and 5 mg/ml (0.05% 0.125%, 0.25%, and 0.5%). Bupivacaine at a concentration of 2.5 mg/ml inhibited the growth of the sensitive S. epidermidis strain, S. pyogenes, and S. pneumoniae, and all of the others except P. aeruginosa at a concentration of 5 mg/ml. Morphine 0.2 and 2 mg/ml (0.02 and 0.2%) did not inhibit any of the strains.

Bacillus cereus↗

Comparative in vitro activity of norfloxacin and seven other antimicrobial agents against clinical isolates from urinary tract infections.

The in vitro activity of norfloxacin, a new quinolone derivative, was tested against 469 clinical isolates derived mainly from urinary samples from outpatients. It inhibited all Escherichia coli, Klebsiella oxytoca and Proteus strains at a concentration of 0.25 micrograms/ml, and all Pseudomonas aeruginosa, Enterobacter, Klebsiella pneumoniae, Staphylococcus and Enterococcus strains at a concentration of 8 micrograms/ml or less. Norfloxacin proved to be more effective than nalidixic acid, trimethoprim, mecillinam and nitrofurantoin against all gram-negative rods tested.

Anti-Infective Agents, Urinary↗

Aminoglycoside resistance among blood culture isolates.

A total of 633 blood culture isolates were collected from 1981 to 1982 from seven major Finnish hospitals, including all university central hospitals. Susceptibility of the strains to gentamicin, tobramycin, amikacin, and netilmicin was determined by the Sensititre microtiter procedure. Resistance against any of these agents occurred in 1.3 to 6.5% of all strains studied. In the Turku University Central Hospital, an increased number of tobramycin- and gentamicin-resistant Staphylococcus epidermidis were found; the frequency of strains resistant to tobramycin was 57% and to gentamicin was 29% versus frequencies of 16 and 18%, respectively, which were observed in the other hospitals. An explanation for this might be a change in the use of aminoglycosides in the Turku University Central Hospital; within 3 years, 1979 to 1981, the consumption of tobramycin and amikacin had increased 330 and 290%, respectively, whereas the use of gentamicin had decreased to 24% of that in the beginning of the period. Resistance against tobramycin was mediated by enzymes APH(2")-AAC(6') and ANT(4').

Amikacin↗

Erythromycin absorption in healthy volunteers from single and multiple doses of enteric-coated pellets and tablets.

The absorption of erythromycin from two different enteric-coated preparations was evaluated in three groups of healthy volunteers. After a single dose, taken after an overnight fast, absorption was significantly better from enteric-coated pellets than from tablets; both the mean peak serum concentration and the peak mean level were higher (p less than 0.01) in all three groups, and the mean area under the serum concentration-time curve (AUC) was at least 65% larger. Eight out of 23 subjects showed no or only a very low serum concentration after the enteric-coated tablets. In a follow-up study, 250 mg doses were given 6-hourly for 3 days, and again the mean maximum serum concentration was significantly higher (p less than 0.05) after the pellets. In conclusion, enteric-coated pellets led to more regular and predictable absorption of erythromycin than did coated tablets.

Adult↗

Penetration of trimethoprim--sulfadiazine into middle ear fluid in secretory otitis media.

Thirty-nine middle ear fluid samples from 23 patients with chronic secretory otitis media were studied. The patients received 3 doses of 3 mg of trimethoprim and 5 mg of sulfadiazine per kg body weight before tympanostomy, the last dose being given 80-270 min (mean 142 min) prior to operation. Mean trimethoprim concentrations were 1.62 micrograms/ml (range 0.8-3.5) and mean sulfadiazine concentrations 10.54 micrograms/ml (range 0-25.0). For most patients the levels exceeded the usual MIC-values for the two commonest pathogens; pneumococci and Haemophilus influenzae. Otitis media caused by beta-lactamase producing Haemophilus is an important indication for trimethoprim-sulfonamide therapy.

Adolescent↗

Streptococcus mutans establishment and dental caries experience in children from 2 to 4 years old.

39 children were studied longitudinally at the age of 2, 3, and 4 yr for the colonization of S. mutans in plaque and saliva and for caries experience. S. mutans was found in 38% of the children, and the predominant serotype group was c/e/f. A total of 16 children got caries before the age of 4. Children who harbored S. mutans in their plaque at the age of 2, appeared to be the most caries-active individuals. Their caries index values (number of decayed, missed and filled surfaces, dmfs = 10.6 +/- 5.3) at the age of 4 differed significantly from the values of children who harbored S. mutans later (dmfs = 3.4 +/- 1.8, P less than 0.005) or remained free from S. mutans infection (dmfs = 0.3 +/- 1.1, P less than 0.0003). It was thus concluded that the early establishment of S. mutans in the plaque of primary incisors indicated early and extensive caries attack in young primary dentition.

Child, Preschool↗

Antibacterial activity of nine oral antibiotics against Streptococcus pneumoniae, Haemophilus influenzae and Branhamella catarrhalis.

The efficacy of nine oral antibiotics were analyzed by the agar dilution method against clinical isolates consisting of 87 beta-lactamase positive and negative Haemophilus influenzae and Branhamella catarrhalis strains and 30 Streptococcus pneumoniae strains. The following drugs were tested: cefaclor, cefalexin, cefadroxil, cefradin, phenoxymethylpenicillin, ampicillin, amoxycillin, erythromycin and doxycycline. Inoculations of 10(4) bacteria/plate were made with a Steers inoculator on Mueller-Hinton agar containing 5% blood. Cefaclor was more effective than the other cefalosporins against all H. influenzae and B. catarrhalis strains, regardless of their beta-lactamase production. Cefaclor and cefradin were more effective than cefalexin and cefadroxil against S. pneumoniae strains. Cefaclor was less effective than erythromycin against pneumococci, B. catarrhalis and beta-lactamase positive H. influenzae strains and equally effective against beta-lactamase negative H. influenzae strains. Cefaclor was less active than doxycycline against the B. catarrhalis and H. influenzae strains and showed similar efficacy as doxycycline against pneumococci.

Anti-Bacterial Agents↗

Preoperative treatment with azlocillin in complicated urinary tract infections.

Eighteen patients, aged 18-84 years, with complicated urinary tract infections admitted to hospital were treated preoperatively with azlocillin (Securopen) for 5 to 10 days. Two patients having chronic pyelonephritis were not operated. Isolates bacteria were Pseudomonas aeruginosa (14), Proteus mirabilis (3), Escherichia coli (2) and Klebsiella spp. (1). Serum concentrations and urine recovery were measured on the fifth day of treatment. The mean serum half-life was 1.85 h and the mean value of the urine recovery 47% of the single dose. On the 5th day of treatment the urine was sterile in 80% of the patients. In 12 patients (60%) the urine was still sterile when controlled 2-6 months after operation and prophylactic postoperative treatment with nitrofurantoin or trimethoprim-sulfamethoxazole.

Adolescent↗

Prophylactic methenamine hippurate or nitrofurantoin in patients with an indwelling urinary catheter.

One hundred and twenty three elderly patients without urinary tract infection who required an indwelling urinary catheter because of cerebrovascular disease were divided into three groups. One was given methenamine hippurate (MH), one nitrofurantoin (NF), while a control group received no prophylactic urinary tract disinfectant. Catheter complications, symptomatic urinary tract infections and the clinical course were recorded. At regular intervals bacteria were cultured from the urine, tests were made for antibody-coated bacteria (ACB) and routine laboratory investigations were performed. NF significantly delayed the appearance of ACB; however, it did not prevent their appearance if a catheter was used for more than two months, by which time ACB were present in most patients irrespective of treatment. MH had less effect on the bacteriological findings, although it significantly decreased the need for antibiotic courses given for treatment of symptomatic urinary tract infections. In both MH- and NF-groups there were fewer patients with mechanical catheter complications. Forty seven patients died, generally due to cerebrovascular disease, and 22 autopsies were performed. Gross inflammatory changes in the urinary tract were commonly found at autopsy in all groups if a catheter had been used for more than two weeks. A positive test for ACB considerably increased the probability of inflammatory changes in the kidneys, but because of the frequency of such changes after prolonged use of an indwelling catheter, the test does not seem to offer much advantage as a guideline for therapy. Prophylactic urinary tract disinfectants may not be warranted in all patients with an indwelling catheter. If, however, recurrent clinical complications such as clogging of the catheter or symptomatic infection occur, continuous use of a urinary tract disinfectant is indicated. MH is preferred because it has fewer side effects than NF.

Aged↗

Some aspects of quantitative bacteriology in burn wounds.

There is clinical evidence that it is important to follow the concentrations of bacteria in burn wounds. This can be done either by quantitative cultures from wound biopsies or from quantitative swab samples or by microscopy. Monitoring by culture is probably better because it gives evidence of the different types of bacteria involved and their antimicrobial sensitivities in advance.

Bacteria↗

Clinical experience with cefamandole in pneumonia.

The efficacy and patient acceptance of i.m. cefamandole 1 000 mg 8 h and 500 mg 8 h, were compared in the treatment of assumed community-acquired pneumonia in 59 hospitalized adult patients. Of 31 patients treated with 1 000 mg 8 h, 94% had a satisfactory clinical response with a 13% bacteriological failure rate. Of 28 patients treated with 500 mg 8 h, 89% had a satisfactory clinical response with a 60% bacteriological failure rate. The only side effect registered was pain at the injection site after doses of more than 1 000 mg. The pain could be eliminated by the addition of 0.5 ml of lidocaine to the drug solution before injection.

Adult↗

Ornidazole and anaerobic bacteria: in vitro sensitivity and effects on wound infections after appendectomy.

The sensitivities of 68 clinical isolates of Bacteroides fragilis, 18 of Clostridium perfringens, and 11 of other Clostridium species were tested against ornidazole alone and in combination with ampicillin and gentamicin. A concentration of 3.1 microgram of ornidazole/ml inhibited 98% of the strains of B. fragilis, with greater sensitivity when ampicillin and gentamicin were also present. A concentration of 6.2 microgram of ornidazole/ml inhibited 16 of 18 strains of C. perfringens and all 11 strains of other Clostridium species. Concentrations in serum and tissue were determined after intravenous infusion of 500 mg of ornidazole 15 min prior to appendectomy. During the operation the concentration in serum was 7.90 +/- 0.57 microgram/ml, and in appendix tissue, 5.26 +/- 0.60 microgram/g. In the series of 200 patients undergoing appendectomy, six patients treated with ornidazole and 12 patients treated with placebo developed a wound infection. In patients with perforated appendix, the rate of wound infection was 7.1% in those given ornidazole and 63.6% in those given placebo (P = 0.004). Not a single B. fragilis was isolated from appendix swabs or wound exudates after prophylaxis with ornidazole.

Adult↗

Short-term treatment of gonorrhoea with intramuscular and oral forms of trimethoprim-sulphamethoxazole.

Fifty-nine male patients and 41 female patients with uncomplicated gonorrhoea were treated with an intramuscular dose of 1600 mg sulphamethoxazole plus 320 mg trimethoprim followed by an oral dose of 2400 mg sulphamethoxazole plus 480 mg trimethoprim 12 hours later. Forty-nine out of 52 male patients and 37 out of 38 female patients who were re-examined were cured. One of the men probably had a reinfection.

Administration, Oral↗

Mezlocillin in the treatment of gonorrhoea.

A single, intramuscular dose of 2 g of mezlocillin was used for the treatment of 158 patients with gonorrhoea. In only three out of 144 patients with urogential gonorrhoea who were re-examined did the treatment fail. Of 12 patients with pharyngeal gonorrhoea who were examined after treatment 10 were treated successfully with the same dose. The sensitivities of the gonococci to mezlocillin and penicillin G correlated well, although mezlocillin seemed to be active at lower concentrations on both highly sensitive and less sensitive isolates.

Female↗