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Biomedical subjects

B Olsson

Publications and source records attributed to B Olsson.

At least 127 records · Page 7Linked to original sources
PubMed1980

Antibiotic resistance patterns of coliform bacteria isolated from food.

308 strains of coliform bacteria isolated from food of various origin were identified and their resistance patterns were studied. The strains belonged to 10 different species and Escherichia coli was the most common. Coliforms isolated from samples incubated at 44 degrees C were more often identified as E. coli than coliforms isolated from samples incubated at 37 degrees C. Klebsiella and Enterobacter spp. taken together were, on the contrary, mor often isolated at 37 degrees C than at 44 degrees C. E. coli was most frequently isolated from raw meat and egg products. Klebsiella dn Enterobacter spp. more often in other types of products. 54% of the strains were resistant to at least one of the 9 antibiotics tested. Resistance to nitrofurantoin and sulphaisodimidine was most frequent (30 and 25% respectively). No strain resistant to streptomycin, neomycin or trimethoprim/sulphamethoxazole was registered. 40% of the resistant strains were multiresistant. The lowest number of resistant strains was recorded from custards and desserts and from raw meat products (42 and 46% respectively) and the highest from ice-cream (89%). Multiresistant strains were recorded most frequently from pasteurized milk products, custards and desserts. None of the 66 multiresistant strains tested could transfer the resistance to E. coli in vitro. The results do not indicate that food of animal origin in Sweden represents a source for bacteria with transferable resistance determinants.

Anti-Bacterial Agents↗
PubMed1979

Absorption of quinidine from an enteric-coated preparation.

The absorption of quinidine from single and multiple doses of an enteric-coated preparation (Systodin) was studied in seven healthy subjects, and was compared with the pharmacokinetics of intravenously administered quinidine and the results of in vitro dissolution tests of the tablets. Absorption of quinidine began after a variable delay, 2-8 h (mean 4.8) after fasting and 3-10 h (mean 6.1) after food. The rate of absorption varied both in and between individuals. It appeared to be lower when the drug was administered after food. Multiple doses after food gave a pattern of plasma concentration-time curves similar to that found on administration of single doses after food. The delay prior to absorption was prolonged at night. The ratio between the maximum and minimum concentration of quinidine during a dose interval varied from 1.3 to 3.2 (mean 2.0). Bioavailability of quinidine in fasting subjects ranged from 69 to 95% (mean 83); variation was greater when doses were administered after food. The release of quinidine from the enteric-coated preparation was pH dependent and was sustained at low pHs as may be found in the intestines. The results indicate that the absorption of quinidine from the enteric-coated formulation was dependent on the highly variable rate of gastric emptying and the pH of intestinal fluid, and it varied greatly both within and between individuals.

Adult↗
PubMed1979

Absolute bioavailability of quinidine in two sustained release preparations.

The bioavailability of quinidine in two sustained release preparations A and B has been compared in three females and three males with i.v. administration of quinidine. The initial rate of oral absorption did not differ between the two drug preparations; the peak concentration was observed after 4 h both for A and B, but was significantly higher after B. A slower decrease in plasma concentration was observed after preparation A than B. Absolute bioavailability did not differ significantly between A (median values 78.4%) and B (median 87.1%). Drug absorption in vivo was in good agreement with the results of in vitro dissolution tests on both preparations. The slower decrease in plasma concentration found for the new sustained release form of quinidine should be of clinical advantage.

Administration, Oral↗
PubMed1979

Effect of oral verapamil on ventricular irregularity in long-standing atrial fibrillation.

In patients with chronic atrial fibrillation (AF), symptoms and cardiac function may be improved by regularizing the ventricular rhythm, even though the AF persists. This study concerned effects of i.v. and oral verapamil (V) on ventricular regularity. A regularizing effect was observed in 5 out of 10 patients after 0.15 mg of V/kg b.wt.i.v., but in only one patient after 80 mg of V By mouth. V in a dose of 240 mg by mouth resulted in ventricular regularity in 6 out of 10 other patients, 320 mg in a further 2 and 400 mg in the remaining 2 patients. Six patients were given chronic oral therapy in progressively increasing doses. Although ventricular regularity and symptom relief were obtained, intolerable side-effects precluded the evaluation of subjective long-term effects of this therapy in all but one patient. Further investigations, particularly concerning the pharmacokinetic mechanisms of V, are needed before the treatment can be recommended for patients with chronic AF.

Administration, Oral↗
PubMed1979

Effects of thoracic epidural block and the beta-1-adrenoreceptor agonist prenalterol on the cardiovascular response to infrarenal aortic cross-clamping in man.

Sixteen patients scheduled for abdominal aortic resection and grafting were randomly assigned to two groups to study the cardiovascular effects of infrarenal aortic cross-clamping. The patients in the first group had received a thoracic epidural block followed by intravenous administration of the selective beta-1-adrenoreceptor agonist prenalterol prior to induction of general anaesthesia. The patients in the second group served as controls and received no specific treatment prior to general anaesthesia. In both groups, aortic cross-clamping was followed by an equal rise in pulmonary artery diastolic pressure and mean systemic arterial pressure. There was a significant difference in systemic vascular resistance, as the control group had a 46% increase 30 s after cross-clamping, while the pretreated patients had only a 7% increase at the same time. Moreover, the patients given the thoracic epidural block followed by prenalterol increased their stroke volume and cardiac indices, as compared to the patients in the control group who showed a significant decrease in these parameters. Possible mechanisms for the mode of action of the combined thoracic epidural block and beta-1-adrenoreceptor agonist pretreatment are discussed.

Adrenergic beta-Agonists↗
PubMed1979

Dental health situation in privileged children in Addis Ababa, Ethiopia.

Two hundred children 6-7 and 13-14 years of age from private schools in Addis Ababa were examined for oral deposits, periodontal condition, dental fluorosis, and dental caries. The findings indicated a higher level of both periodontal disease and dental carries in the privileged children than in previously surveyed nonprivileged children in Ethiopia. This difference was attributed to a higher sucrose intake in the privileged group. The findings may illustrate a dental health situation that will inevitably develop in Ethiopia with a continuous increase in the sucrose consumption.

Adolescent↗
PubMed1979

Dental findings in high-fluoride areas in Ethiopia.

A survey comprising 478 children aged 6-7 years and 13-14 years was conducted in high-fluoride areas (Wonji, 12.4 parts/10(6) F- and Awassa, 3.5 parts/10 F-) in the Rift Valley in Ethiopia. Dental fluorosis was found in 99% of the 6-7-year-old groups. Very mild to moderate fluorosis dominated in the primary teeth and moderate to severe fluorosis in the permanent teeth. All 13-14-year-old children born in Awassa of Wonji had fluorosis, mainly in the moderate to severe form. Eighty-four percent of the 13-14-year-old children not born in the area had fluorosis, mainly in the very mild form. The most severe fluorosis was seen in the last erupting teeth, but moderate fluorosis was also seen in primary incisors, indicating placental transfer of fluorides. Teeth with moderate and severe fluorosis more frequently had dental caries than teeth with no or very mild and mild fluorosis. The average DMFT was 2.46 +/- 2.34 in Wonji and 1.69 +/- 1.88 in Awassa. The average dft was 0.32 +/- 0.80 in Wonji and 0.40 +/- 0.96 in Awassa. Gingivitis was seen in 97% of the children and the average OHI-S was 1.94 +/- 0.71.

Adolescent↗
PubMed1979

Factors contributing to resistance to beta-lactam antibiotics in Bacteroides fragilis.

Fifteen strains of Bacteroides fragilis, five highly resistant, five moderately resistant, and five susceptible to benzylpenicillin and cephaloridine, were tested for beta-lactamase production. In the highly resistant and the moderately resistant groups of strains, a correlation between formation of beta-lactamase and minimal inhibitory concentrations was demonstrated. In the presence of the beta-lactamase inhibitors clavulanic acid and CP-45,899 at concentrations of 1 mug/ml, the susceptibility to cephaloridine increased fourfold or more in the beta-lactamase-producing strains. Crypticity measurements (beta-lactamase activity broken/intact cells) with cephaloridine as substrate could indicate a diffusion barrier in the cell wall.

Anti-Bacterial Agents↗
PubMed1978

Efficiency of traditional chewing sticks in oral hygiene programs among Ethiopian schoolchildren.

The effect of oral hygiene programs was studied in 248 children from five schoolclasses in Asella, Ethiopia. All children received professional toothcleaning after an initial clinical examination, and were again examined after a trial period of 3 months. The classes were assigned to the following procedures: one class received information and instruction in the use of the toothbrush, and a second class in the use of the mefaka, a wooden chewing stick traditionally used for oral cleaning. The children were advised to clean their teeth daily. Two other classes received similar information and instruction with regard to the toothbrush and the mefaka. Oral cleaning was then performed daily under direction and supervision, in one class with the toothbrush and in the other class with the mefaka. The fifth class was used as control. Instruction only was found to have no effect on the amount of oral deposits. Supervised oral cleaning, on the other hand, improved the oral hygiene of the schoolchildren significantly. The mefaka was found to be as effective as the toothbrush in removing oral deposits. It was concluded that the mefaka should be recommended for use in preventive dental programs in Ethiopia since it is effective, inexpensive, and familiar to the population.

Adolescent↗
PubMed1978

Periodontal disease and oral hygiene in Arussi province, Ethiopia.

A dental health survey was conducted in the Arussi province in Ethiopia. The survey comprised 1,700 persons between 6 and 54 years of age in five age groups from four regions of the province. Findings concerning periodontal disease and oral hygiene are reported in the present paper. The onset of periodontal disease was early, with 60% of the children in the 6-7 year group having gingivitis. In general, periodontal disease was found in a majority of the surveyed population (83%). Severe periodontal destruction was, however, unusual before the age of 30, but at the age of 45-54 years 52% of the sample exhibited pocket formation. The level of periodontal disease in Ethiopia was judged as low to moderate. A close relationship was observed between oral cleanliness and periodontal condition. A possible favorable influence of the diet and traditional oral cleaning methods is conceivable.

Adolescent↗
PubMed1978

Dental caries and fluorosis in Arussi province, Ethiopia.

A dental health survey was carried out in the Arussi province in Ethiopia. The survey comprised 1,700 persons between 6 and 54 years of age in five age groups from four areas of the province. The present paper deals with findings on dental fluorosis and dental caries. Dental fluorosis was found in 18% of the subjects, mainly in a very mild form. The fluoride content of the water (0.2-0.3 part/10(6) F-) in combination with a high tea consumption was assumed to give a fluoride intake optimal for caries prevention. The prevalence of dental caries was low. Thirty-eight percent of the 6-7-year-old group had decayed primary teeth and 51% of the total sample had decayed permanent teeth. Comparisons with a study from 1958 revealed that the prevalence of dental caries had increased in the last few decades, probably due to the recently adopted habit of using sugar in the diet.

Adolescent↗
PubMed1978

beta-lactamases in bacteroides.

Bacteroides fragilis is responsible for most anaerobic infections in man. Most isolates of B. fragilis show resistance to beta-lactam antibiotics. This resistance might be due to beta-lactamase production or permeability barrier in the cell wall. B. fragilis produce beta-lactamase with mainly cephalosporinase activity. Other Bacteroides species such as B. clostridiformis, B. melaninogenicus and B. oralis also produce beta-lactamase but with different biochemical characteristics.

Amidohydrolases↗
PubMed1977

Susceptibility to beta-lactam antibiotics and production of beta-lactamase in Bacteroides fragilis.

Using the agar dilution technique, 231 strains of Bacteroides fragilis, isolated during a 2-year period from human infections, were identified at subspecies level and were tested for susceptibility to 13 beta-lactam antibiotics. The penicillins were benzylpenicillin, ampicillin, carbenicillin, cloxacillin, and the recently described penicillin derivatives cyclacillin, ticarcillin, and PC-904. The following cephalosporin derivatives were tested: cephaloridine, cephalothin, cephalexin, cefamandole and cefuroxime. The cephamycin C derivative cefoxitin was also included in the study. Cefoxitin was the most effective drug tested since more than 80% of the strains were inhibited by 8 microgram/ml or less, and no strain had a minimal inhibitory concentration (MIC) of more than 64 microgram/ml. There was no marked difference in sensitivity among the subspecies with exception of subspecies vulgatus, which was slightly more sensitive to all antibiotics tested. The size of the inoculum was an important factor for obtaining reproducible results in the sensitivity tests. Increased inocula resulted in markedly higher MICs for cephaloridine and cefuroxime. Production of beta-lactamase was performed on all isolates by a chromogenic cephalosporin substrate and about 90% of the strains were found to be beta-lactamase producers.

Amidohydrolases↗
PubMed1977

The kinetics of reoxidation of reduced benzylamine oxidase.

1. The mechanism of reoxidation of reduced benzylamine oxidase has been investigated at different pH between 6 and 10 by steady-state and transient-state kinetic methods. 2. The reoxidation process involves minimally a second-order interaction between reduced enzyme and oxygen leading to the formation of a spectrally modified enzyme intermediate, and a subsequent first-order step converting this intermediate into free enzyme. The variation with pH of rate constants according to such a reaction scheme is reported. 3. Under aerobic conditions the oxygen-independent reaction represents the main rate-limiting step in the catalytic process at alkaline pH. At neutral or acid pH the interaction between reduced enzyme and oxygen becomes mainly rate-limiting, indicating that the concentration of oxygen may be a critical factor controlling enzyme activity under physiological conditions. 4. The spectrally modified intermediate formed during the reoxidation process exhibits a difference-absorption band centered around 290 nm in comparison to free enzyme, and an additional difference-absorption band at 470 nm in comparison to reduced enzyme. These data indicate that formation of the intermediate, besides leading to a reappearance of the 470-nm absorption band disappearing on reduction of the enzyme, results in a spectral perturbation of one or several aromatic amino-acid residues in the protein. This perturbation could possibly reflect a conformational change of the enzymes.

Benzylamine Oxidase↗
PubMed1977

Estimation of ventricular refractoriness in man by the extra stimulus method.

The effective right ventricular refractory (EVRP) period was estimated in 24 patients using the extra stimulus technique. All patients were paced from the right ventricle at basic pacing intervals of 400, 500, 600 and 800 ms, respectively. In all patients the EVRP decreased when the basic pacing rate was increased. At the same basic pacing rate there was a wide variation in the EVRP between individual patients. Within an individual patient, however, providing the position of the pacing electrode remained stable, there was no significant variation in the EVRP when estimations were performed 15-30 min apart. Thus the technique can be used to assess the effect of a drug on the EVRP in an individual patient.

Adult↗