PubMed Health⌕ Search

Biomedical subjects

S Edwardsson

Publications and source records attributed to S Edwardsson.

At least 19 recordsLinked to original sources
PubMed1992

Purification and properties of sorbitol-6-phosphate dehydrogenase from oral streptococci.

The activity of sorbitol-6-phosphate (S6P) dehydrogenase (S6PDH) and the sorbitol transport system were studied in strains of the oral streptococci Streptococcus gordonii, Streptococcus mitis, Streptococcus sanguis and Streptococcus mutans. Genetically transformed (to ferment sorbitol) strains and their DNA donors were included. S6PDH was purified by anion exchange chromatography and gel filtration. The purity of the enzyme was confirmed by polyacrylamide gel electrophoresis. The purified enzyme from all the strains exhibited Michaelis-Menton saturation kinetics. The Km values for nicotinamide-adenine dinucleotide (NAD) and S6P ranged between 0.03 and 0.21 mM and 0.07 and 0.20 mM respectively. The relative molecular weights of the native enzyme were 229,000 for one donor-transformant pair (S. sanguis and S. gordonii), 107,000 for the other pair (S. mitis and S. gordonii) and 129,000 for S. mutans. The molecular weights of the S6PDH subunits ranged from 26,000 to 28,000. The pH optima (greater than 8.5) and the amino acid composition (15 amino acids examined) were similar for the S6PDH from the different strains. However, the chromatographic and electrophoretic patterns as well as the Km values for NAD and S6P were the same only between the S6PDHs from the strains within each donor-transformant pair. Purified S6PDH from S. mutans also exhibited low mannitol-1-phosphate dehydrogenase activity. Sorbitol-grown decryptified cells of all the strains phosphorylated sorbitol in the presence of phosphoenolpyruvate but not in the presence of adenosine triphosphate (ATP). ATP-mediated phosphorylation of glucose was observed with the same strains when grown on glucose. No evidence for a non-phosphotransferase transport system was found for sorbitol in any of the strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport, Active↗
PubMed1992

The effect of topical metronidazole therapy on experimentally-induced periodontitis in the beagle dog.

The present study was performed to assess the effect of topical metronidazole therapy on ligature-induced periodontitis in beagle dogs. 6 beagle dogs with experimentally-induced periodontitis on the mandibular 2nd, 3rd and 4th premolars were treated with metronidazole 10% dental paste 2 x daily for 4 weeks in an open placebo-controlled study using a split-mouth design. Recordings of probing pocket depth, bleeding on probing and gingival index were performed before commencement of treatment and repeated weekly during the 4-weeks treatment period. Concurrently, samples for microbiological analysis were collected from 2 of the dogs. The results demonstrated that probing pocket depth, bleeding on probing and gingival index had improved significantly in the metronidazole-treated side compared with the placebo-treated side. Black pigmented Bacteroides spp. and Spirochetes, present in all samples before treatment, were eliminated from the metronidazole-treated side after the 1st week of treatment and throughout the treatment period, whereas they were present in all samples from the placebo-treated side. The result of the present study demonstrates that topical application of metronidazole in a dental paste, improves the clinical features of the experimentally-induced periodontitis and eliminates some of the micro-organisms associated with the disease.

Animals↗
PubMed1992

Influence of transient salivary flora on assessment of mutans streptococci level by the "Strip mutans" method.

The Dentocult SM ("Strip mutans") method occasionally shows decoloration of broth and of colonies of mutans streptococci on the plastic strip, thereby making interpretation difficult. In an attempt to explain the phenomenon and to investigate the influence of the salivary flora on the "Strip mutans" method, a total of 46 subjects were sampled. Saliva was analyzed using the "Strip mutans" method and conventional plating techniques to identify mutans streptococci, enterococci, staphylococci, enteric bacteria, and yeasts. Approximately 85% of the "Strip mutans" scores coincided with the conventional MSB-plating method. Two samples showed decolored mutans streptococci colonies on the "Strip mutans" strip. Enterococcus spp. were present in the saliva of these test subjects and could grow in the "Strip mutans" broth. Enterococcus faecalis was able to induce the same type of decoloration under experimental pure culture conditions. Three "Strip mutans" samples showed small colonies of mutans streptococci, visible only under magnification (x 10-20). Staphylococcus epidermidis was present in these saliva samples and showed heavy growth in the broth. Under experimental pure culture conditions S. epidermidis also inhibited the growth of mutans streptococci to some extent.

Adult↗
PubMed1992

Rinsing with delmopinol 0.2% and chlorhexidine 0.2%: short-term effect on salivary microbiology, plaque, and gingivitis.

The aim of this short-term study was to compare the effect of delmopinol HCl 0.2% and chlorhexidine digluconate 0.2% rinses on the development of dental plaque, the healing of experimental gingivitis, and the salivary microbiology. As part of a larger study protocol, 45 healthy males enrolled in an oral hygiene program to upgrade their oral health. For this portion of the study, participants had their teeth professionally cleaned on day 0. The participants then abstained from standard mechanical oral hygiene procedures, but applied a placebo solution twice daily for 2 weeks. At the end of this period the subjects received a second professional cleaning and were then assigned to 2 treatment groups: Group 1 rinsed with 10 ml of delmopinol HCl 0.2% and Group 2 rinsed with 10 ml of chlorhexidine digluconate 0.2% for 1 minute twice daily for the next 2 weeks and continued to refrain from mechanical oral hygiene procedures. At the end of the placebo and active treatment periods 1) saliva samples were taken and cultivated on a series of media; 2) the degree of gingivitis was assessed with gingival crevicular fluid (GCF) and gingivitis index (GI); and 3) the plaque index was assessed and the stainable buccal plaque extension was analyzed planimetrically. No changes in the salivary microbiological counts were detected for the subjects rinsing with delmopinol. Subjects rinsing with chlorhexidine showed significant reductions of anaerobes, aerobes, and S. mutans in saliva. The amounts of GCF and GI were reduced largely to the same extent in both treatment groups. Mean plaque extension was reduced by 52% after delmopinol and 88% after chlorhexidine rinsing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Antimicrobial effect of a dental varnish, in vitro.

The effects of a polymer based antimicrobial releasing varnish Cervitec were investigated against different gram-positive and gram-negative bacterial strains as well as a yeast using the agar diffusion inhibitory test (ADT-test in vitro). As positive controls a 1% chlorhexidine gel and 1% aqueous solution of thymol and a placebo polymer varnish without active agents were employed. The test experimental varnish containing 1% chlorhexidine and 1% thymol showed antimicrobial activity against all gram-positive and gram-negative microorganisms tested including one Candida strain. The positive controls were similar in effect compared to the test varnish. No antimicrobial effect was observed with the placebo varnish without active ingredients. Toothpicks and dental floss treated with the test varnish showed an antimicrobial effect against S. mutans even after storing in room temperature up to 12 months. The results from this study support earlier laboratory studies that chlorhexidine and thymol diffuse out of the experimental varnish and that the varnish is active against various of oral pathogens. The possibility to use toothpicks or dental floss impregnated with the varnish with the aim to become chemotherapeutically active against periodontal diseases as well as against dental caries, is promising and should be tested in vivo.

Actinomyces viscosus↗
PubMed1991

Mutans streptococci in saliva and interdental spaces after topical applications of an antibacterial varnish in schoolchildren.

The effect of a chlorhexidine-containing varnish on the levels of mutans streptococci in saliva and in interdental spaces was investigated in 33 15-year-old schoolchildren. Each child was treated with an active (1% chlorhexidine; 1% thymol) and a placebo varnish preparation following the split-mouth technique. The varnishes were applied twice in small amounts into upper interdental areas with a 2-d interval. Mutans streptococci in saliva and interdental plaque was sampled and enumerated during 3 months. The results showed an immediate reduction of the number of interdental mutans streptococci on both test and placebo side after the varnish applications. The levels, however, were significantly lower in the test quadrants compared with the placebo-treated sides after 8, 30 and 90 d. Thus, the findings indicate a slower recolonization in interdental spaces treated with the active preparation. The levels of mutans streptococci in saliva were significantly reduced 1 and 3 months after varnish treatment, suggesting a long-term effect of the antibacterial varnish.

Adolescent↗
PubMed1991

Effect of delmopinol on in vitro dental plaque formation, bacterial acid production and the number of microorganisms in human saliva.

This study investigated the effect of a surface active compound, delmopinol, on plaque formation and established plaque in vitro, on the bacterial acid production from glucose and on the total viable bacterial counts in saliva. The antimicrobial effect was compared with that of chlorhexidine. The plaque-inhibiting effect was evaluated in an artificial mouth system, and the effect on bacterial acid production was registered as a decrease of pH in bacterial suspensions with various concentrations of delmopinol. It was shown that delmopinol is able to prevent plaque formation, to dissolve established plaque in vitro, and that it has 5-125 times higher minimum inhibitory concentrations than chlorhexidine. Saliva samples collected 1 min after rinsing with delmopinol showed on differences in the total number of bacteria in saliva as compared with controls. It was also shown that the bacterial acid production from glucose was reduced successively with increasing concentrations of delmopinol. The results indicate that delmopinol might be as effective as chlorhexidine against plaque formation and that delmopinol is capable of penetrating established plaque, thus promoting a more effective mechanical cleansing.

Anti-Infective Agents, Local↗
PubMed1991

Human lactoferrin binding to Porphyromonas gingivalis, Prevotella intermedia and Prevotella melaninogenica.

Human isolates of Porphyromonas gingivalis (n = 16), Prevotella intermedia n = 82) and Prevotella melaninogenica (n = 18) from diseased periodontal pockets were examined for interaction with human lactoferrin (HLf) in a standardized 125I-labeled protein binding assay. The highest HLf binding was found in P. intermedia strains, followed by P. gingivalis and P. melaninogenica. Further characterization of the interaction was performed with 1 representative strain from each species. HLf binding to P. gingivalis reached a saturation instantly and was optimal at pH 5.0-6.5. The corresponding values for P. melaninogenica were 90 min and pH 3.0-5.5. The HLf binding to the 2 strains seem to be nonspecific. In contrast, P. intermedia demonstrated specific binding, and a time-saturability within 60 min with an optimal uptake at pH 6.0-7.5. Scatchard analysis implied 45,000 receptors per cell with an affinity constant of 5.5 x 10(-7) M on P. intermedia strain 4H. The binding capacity in all 3 strains was affected by the culture medium. HLf binding components in these strains were susceptible to heat or proteases. Binding was eliminated in P. gingivalis and was enhanced in P. intermedia and P. melaninogenica by periodate treatment. Unlabeled HLf or bovine lactoferrin effectively displaced labeled HLf binding. Various proteins and carbohydrates did not inhibit HLf binding. Our data suggest that HLf binds to these periodontitis-associated species and that this mechanism is distinct from the previously known ligand interactions in oral bacteria.

Acute-Phase Proteins↗
PubMed1991

Effect of partial substitution of invert sugar for sucrose in combination with Duraphat treatment on caries development in preschool children: the Malmö Study.

The aim was to study the effect of substitution of invert sugar for sucrose, in combination with fluoride varnish (Duraphat) treatment twice a year, on caries development in preschool children. One hundred and eighty-seven 4-years-olds were divided randomly into four sugar groups: (1) sucrose (S), (2) sucrose-Duraphat (SD), (3) invert sugar (I), and (4) invert sugar-Duraphat (ID). All families were asked to buy beverages, biscuits, breakfast cereals, marmalade, ice cream, jam, ketchup, sweets and table sugar, totally 32 different food items, sweetened with invert sugar or sucrose. The substitution was, thus, restricted to a number of sugar-rich between-meal products. The study was carried out double-blind for 2 years. The children of those parents who did not want to participate in the sugar groups were divided randomly into one of the following two groups: (5) Duraphat (D), and control (C). Because of lack of cooperation, only 114 of the 187 children (61%) were considered to have completed the study. The mean caries increment, including initial lesions, was 3.86 dmfs in the combined groups S and SD (n = 63) and 3.10 dmfs in the combined groups I and ID (n = 51) during the 2 years (p = 0.34). The corresponding values for the 2nd year only were 1.84 and 0.67 dmfs, respectively (p = 0.09). The mean caries increment was 2.86 dmfs in group D (n = 113) and 4.10 dmfs (p = 0.08) in group C (n = 93). If initial caries lesions were excluded from the index, the difference between groups D and C was significant (p = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)

Cariogenic Agents↗
PubMed1991

Secondary caries related to various marginal gaps around amalgam restorations in vitro.

Secondary caries lesions were produced in vitro by immersing human tooth-blocks with amalgam restorations every third day for 4 weeks in glucose- or sucrose-containing broth inoculated with a strain of Streptococcus mutans. The lesions at the cavity walls were related to various standardized micro-spaces (0, 30, 40, 60 and 80 microns) around the restorations. When a thick, sucrose induced layer of plaque covered the margin, dentine caries was found in all cases where a gap was present (30 microns or more). In the presence of a thin, glucose induced layer of plaque, dentine caries was detected only in the specimens with 60 and 80 microns gap-widths. Caries lesions were detected on the outer free enamel surfaces in all specimens. Lesions in the enamel of the cavity walls were observed with polarized light in 46% in the presence of sucrose- and in 21% in the presence of glucose-induced plaque.

Dental Amalgam↗
PubMed1979

Bacteria beneath composite restorations--a culturing and histobacteriological study.

The occurrence, viability and identification of the microbial flora under composite fillings using an anaerobic technique were studied. Class V cavities were prepared on clinically healthy buccal surfaces of 7 contralateral pairs of premolars in children 11--15 years of age. After preparation, rubber dam was applied and one cavity in each pair of teeth was washed with water blasted dry with air and filled with Adaptic. The other cavity was washed with a cavity cleaner (Tubulicid) and a cavity liner (Tubulitec) was applicated prior to filling with Adaptic. The teeth were extracted after 4--6 weeks. Under anerobic conditions the tooth crown was split. From one half samples were taken from the pulpal wall under the filling and cultured on blood agar and in broth medium. The other half was examined with histobacteriological technique. No growth occurred in cultures from lined cavities but in 6 of the 7 unlined cavities. Full agreement was observed between the findings from the culturing and histobacteriological examinations concerning presence or absence of microorganisms at the pulpal wall in all 14 teeth. The flora was mixed. Gram-positive bacteria, mainly Streptococcus and Actinomyces, dominated over gram-negative bacteria including Veillonella, Fusobacterium, Campylobacter and Selenomonas. The composition of the flora was more similar to that observed in dental plaque than that found in carious dentin or in saliva in other studies.

Adolescent↗
PubMed1979

Effects of 3 months frequent consumption of hydrogenated starch hydrolysate (Lycasin), maltitol, sorbitol and xylitol on human dental plaque.

Lozenges containing hydrogenated starch hydrolysate (Lycasin), maltitol, sorbitol or xylitol were consumed 4 times daily during 3 months by 4 groups of persons (in all 85 subjects). In the maltitol-, sorbitol- and xylitol-group the plque wet weights were of the same magnitude before and after the test period. In the Lycasin-group, a higher value was found after than before the 3-month period (p less than 0.01). The acid production in suspensions of dental plaque material from Lycasin, maltitol and sorbitol expressed as per cent of that from glucose was approximately the same before and after the test period. From xylitol no acid production could be demonstrated either before or after the 3-month period. There were no statistically significant differences between the plaque pH-changes induced by rinsing with 50% solutions of Lycasin, maltitol, sorbitol or xylitol before and after the test period. However, there was a tendency (p less than 0.05) towards lower pH-values induced by the maltitrol and sorbitol rinse after the 3-month period compared with before. No difference in the relative numbers of facultative anaerobic streptococci. Streptococcus mutans or facultative anaerobic lactobacilli before and after the test period was found.

Adult↗
PubMed1977

Acid production from Lycasin, maltitol, sorbitol and xylitol by oral streptococci and lactobacilli.

The acid production from maltitol was compared with the acid production from hydrogenated starch hydrolysate (Lycasin), sorbitol and xylitol by a number of oral strains and reference strains of Streptococcus mutans, S. sanguis, S. salivarius, S. mitior, S. milleri, S. faecalis, S. faecium, S. avium, Lactobacillus casei and L. salivarius. The polyols were added to a final concentration of 1.0% to two different basal media. Incubation was performed at 37 degrees C for 7 days after which the pH was recorded. Maltitol was fermented only by the lactobacilli (about two thirds of the strains). Lycasin was fermented by all strains of S. faecalis, more than 90% of the lactobacilli, about half of the S. sanguis strains, about one third of the S. mutans strains, and by a few other streptococcal strains. Acid production from sorbitol was observed among more than 80% of the S. mutans strains and the S. faecalis strains and most of the lactobacilli strains. Sorbitol-fermenting strains of S. sanguis and of S. mitior, all isolated from sorbitol-consumers, were observed. No other sorbitol-fermenting streptococci were found. Only the reference strains L. salivarius subsp. salivarius ATCC 11741 and S. avium ATCC 14025 fermented xylitol.

Acids↗