Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of mutants defective in caries-associated traits has enabled the genetic dissociation of agglutination from adhesion, the demonstration of serotype-specific contributions of IPS to virulence, the importance of glucanohydrolase to virulence to a greater degree than to plaque formation, and the apparent lack of importance of agglutination to virulence. We have also been able to demonstrate the ability of plaque formation-defective mutants and other variants both to infect and to emerge, yet not to cause disease. Additional mutants, currently under study in our laboratory include fructanase, invertase, and sucrose permease-defectives. Ultimately, the identification of key, probably surface-associated virulence factors will offer more potent and specific antigens for directed immune responses by the host.
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PMID:Genetic alterations of Streptococcus mutans' virulence. 3 44

The effects of increased and low dietary sucrose levels on the biochemical activities and composition of 4- and 12-day plaque were investigated in eight young men. The subjects were fed supervised, nutritionally adequate diets. Dextran hydrolase, levan hydrolase, and total carbohydrate content were increased during a sucrose-rich diet while invertase activity was decreased. Base-extractable carbohydrate was decreased in four-day plaque during the sucrose-rich diet. Glucosyltransferase and fructosyltransferase activity, buffer-soluble carbohydrate, and buffer-soluble protein were also determined.
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PMID:Effects of dietary sucrose levels on extracellular polysaccharide metabolism of human dental plaque. 105 73

Dental plaque material, collected from five subjects, was pooled, homogenised and sonicated. The cell-free extracts and the remaining plaque suspension were incubated with sucrose. Approximately 14 per cent of the total "sucrase" activity was found in the cell-free extracts after homogenisation, 46 per cent in the cell-free extracts after sonication and 40 per cent in the remaining plaque suspension containing cell-fractions, respectively. Using gel chromatography of pooled plaque extracs from 10 subjects, active fractions were incubated with sucrose. The reaction products were isolated and characterised. The results indicate the presence of at least three groups of sucrose-splitting enzymes: dextransucrase, levansucrase and invertase.
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PMID:Separation of "sucrases" in supernatants of human dental plaque material and characterisation of the reaction products. 105 54

The effects on plaque induced by the use of xylitol- and sucrose-containing chewing-gums were studied on ten test-persons with neglected oral hygiene during two three-day periods. The chewing of three, as well as of ten pieces per day of a xylitol chewing-gum resulted in a significantly reduction in the amount of plaque and in the decrease of activity of invertase-like enzymes in plaque extracellular phase, when compared to corresponding conditions where a sucrose-containing chewing-gum was used.
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PMID:Effect on plaque of a xylitol-containing chewing-gum. A pilot study. 106 31

The effects on plaque induced by single or repeated use of xylitol- and sucrose-containing chewing-gums were studied on twenty subjects refraining from tooth-brushing for three days. Mechanical removal of plaque by chewing during a single period was shown to yield no significant differences between gravimetric values obtained before and after chewing. Daily use of a xylitol-containing chewing-gum reduced by 47% the weight of plaque formed in comparison to a sucrose-containing product, and by 20--41% in comparison to conditions when no chewing-gum was used. The use of a xylitol chewing-gum induced a lower invertase-like activity in plaque extra cellular phase. Results at variance with the gravimetric data were obtained by using a stained plaque scoring system; the eventual inadequacy of such plaque scoring systems was discussed.
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PMID:Effect on plaque of a xylitol-containing chewing-gum. A clinical and biochemical study. 106 32

The aim of the present study was to further investigate the plaque-reducing effect of a xylitol-containing chewing gum. Ninety-six dental students were divided randomly into three groups: a sucrose group (n = 32), a xylitol group (n = 36) and a control group (n = 28), using a sucrose-containing chewing gum, a xylitol-containing chewing gum, or no chewing gum, respectively, during a three-day experimental plaque growth period with restricted oral hygiene. The fresh weight of plaque collected in the xylitol group was 40% lower than in the sucrose group, along with a significantly lower mean plaque index. The use of the xylitol chewing gum induced low invertase-like activity in plaque extra-cellular phase together with low carbohydrate content. These results concur to indicate advantageous effects through the use of a xylitol-containing chewing gum.
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PMID:Effect of a xylitol chewing gum on plaque quantity and quality. 106 26

The relative effects in human dental plaque material from the three main extracellular sucrolytic enzymes from bacterial origin, invertase, dextransucrase and levansucrase, have been investigated by means of quantitative determination of products with sucrose as the substrate. Twenty young men having carious lesions and harboring plaque material on the tooth surfaces, were selected. One gram (wet weight) of plaque material was obtained and divided in five samples, 0.2 g each, for different investigations and controls. Twice as much fructan as glucan was found in plaque. Invertase activity was found to dominate sucrolysis within plaque with 99.67% of the total activity.
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PMID:Relative effects of sucrolytic enzymes in human dental plaque. 107 Jan 29

The in vitro dextran-sucrase activities and adherence to glass of S. mutans 6715 and PS14 wild types and mutants were quantitated and compared with their in vivo cariogenicity in young, gnotobiotic rats. In general, S. mutans PS14 mutants B414 and B421 and 6715 mutant C4 demonstrated less dextran-sucrase activity and adherence than parental strains and caused fewer carious lesions in gnotobiotic rats. Rats monoinfected with either PS14 mutants B414 or B421 had less plaque and viable S. mutans in plaque than rats infected with parental strain. Both S. mutans 6715 mutants C211 and C229, demonstrated greater enzyme activity and adherence than the parental strain and produced more carious lesions.
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PMID:Virulence of Streptococcus mutans: biochemical and pathogenic characteristics of mutant isolates. 120 67

The study was part of a series of investigations aiming at the development of diagnostic caries tests for screening of risk subjects. The material consisted of 100 adult subjects (mean 62 yr, range 47-79 yr), 50 of these under chronic medication. The series of tests included two chairside registrations, i.e. incipient demineralization of exposed root surfaces without cavitation (RD 1) and quantitation of visible plaque (VPT%), three microbiological tests for mutans streptococci, lactobacilli, and candida/yeasts and three tests on stimulated saliva, i.e. secretion rate, buffering capacity and sucrase activity. A thorough clinical examination was conducted at the baseline and 1-yr registration phases, caries being registered at a tooth surface level according to WHO recommendations separately for coronal and root caries. Considerably more root caries than coronal caries developed during the observation period. For coronal caries increment, the predictive value of any of the tests was not significant. For root caries, however, the association between several tests and prospective caries increment was significant. Subsequent multifactorial modeling yielded the highest predictive value to the combination of Past Root Caries Experience (OR 25.0, Visible Plaque (OR 4.2), Candida (OR 8.0) and Lactobacilli (OR 5.8). A positive finding of Past Root Caries (RDFS) or the combination of the other three tests (Can, LB, VPT%) as criteria for selection in screening for root caries produced good accuracy (84.0) and a relative risk of 5.5.
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PMID:Multifactorial modeling for root caries prediction. 154 10

The parameters related to an intraoral mineralization tendency in periodontitis-affected (P+) and periodontitis-free (P-) study subjects (16 adults, 46-74 yr, matched for sex and age) were compared. For this purpose the calcium (Ca) and phosphate (P) concentration of both plaque and saliva, resting pH and the acidogenic response of interdental plaque, plaque wet weight, salivary flow rate, buffering capacity and sucrase activity, interdental plaque, plaque S. mutans levels as well as salivary lactobacilli and yeast levels were estimated. Plaque Ca (micrograms/mg protein, P less than 0.025) and P (micrograms/mg protein, P less than 0.05), saliva Ca (micrograms/ml, P less than 0.005) and the saliva Ca:P ratio (P less than 0.005) were higher in the P+ than in the P- group. The resting pH values were higher (P less than 0.025) and the acidogenic response of the interdental plaque was lower (P less than 0.025) in the P+ group than in the P- group. The P+ group had lower S. mutans levels in saliva and interdental plaque. No differences were found in the wet weight of plaque and in the flow rate, buffering capacity or sucrase activity of saliva between the groups. The findings of the mineralization-related parameters in the two "extreme" groups of periodontal status suggest a higher intraoral mineralization tendency in periodontitis-affected persons than in periodontitis-free subjects. Ca and P accumulation of supragingival plaque seem to be connected with low acidogenicity of plaque and high salivary Ca concentration.
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PMID:Comparative study on mineralization-related intraoral parameters in periodontitis-affected and periodontitis-free adults. 239 26


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