摘要:

The initial step in the lactoperoxidase (LPO) catalysed oxidation of thiocyanate (SCN––) by hydrogen peroxide (H2O2) leads to the formation of hypothiocyanite (OSCN––), the ion of hypothiocyanous acid. In dilute non-acid solutions, the compound is much more stable than previous investigations have suggested. OSCN–– was prepared non-enzymatically, by the hydrolysis of thiocyanogen (SCN)2 in strongly alkaline solution. These solutions were inhibitory towards bacteria, in the same way as the LPO preparations. OSCN–– oxidises thiol groups, and during this reaction SCN–– is regenerated. Since the inhibitory effect of the LPO system has been shown to be due the oxidation of enzymes containing essential thiol groups, it is postulated that OSCN–– is identical to the inhibitor. The over-all mechanism can be explained by an interference in the NADH-NADPH balance of the cell. In the presence of LPO the oxidation of NADH, giving H2O2, results via OSCN–– in the oxidation of thiols. For their reduction again,

ISSN:0008-6568    

DOI:10.1159/000260252

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Dental plaque formation is initiated by adsorption of bacteria to the acquired enamel pellicle, which is known to contain blood group substances. In the present study, human red blood cells were used as targets for plaque bacteria and bacterial products and haemagglutination was observed. Sucrose-grown, but not glucose-grown Streptococcus mutans strains caused haemagglutination. In contrast, strains of Streptococcus sanguis, Streptococcus mitior and Actinomyces viscosus agglutinated red cells irrespectively of sucrose in the medium. Soluble and insoluble polysaccharides prepared from cultures of Strep. mutans caused haemagglutination, whereas linear, commercial polysaccharides were ineffective. Total plaque from sucrose-fed monkeys, as well as a high proportion of bacterial strains adsorbed to smooth tooth surfaces of monkeys during a 3-hour period, caused haemagglutination. The factors determining the haemagglutinating ability of these plaque-forming microorganisms are discussed. Adsorption of oral microorganisms to red blood cells may constitute a model system from which data related to initial bacterial adsorption to teeth can be obtained.

ISSN:0008-6568    

DOI:10.1159/000260253

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Ethane-1-hydroxy-11-diphosphonate (EHDP) is able to inhibit anaerobic growth as well as anaerobic acid production of Streptococcus mutans, probably by its chelating capacity. The effects depend on the age of the organism and are influenced by Mg2+ and PO43––ions. This suggests that EHDP not only inhibits caries by diminishing the solubility of enamel but also by its action on a particularly cariogenic microorganism in dental pla

ISSN:0008-6568    

DOI:10.1159/000260254

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Newborn Osborn-Mendel rats were injected daily for 14 days with tritiated proline. After weaning they were fed on a cariogenic diet. Radioactive material, normally located in the intertubular matrix, was found in the bacteria-rich contents of the carious tubules, dilated tubules, microcavities and large cavities in the altered tissue, and in the gap of the amelo-dentinal junction. Electron microscopical studies under way might give more precise information on the location of the isotope at an ultrastructural level.

ISSN:0008-6568    

DOI:10.1159/000260255

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

To elucidate further our previous findings on the corrective effects of dietary magnesium, phosphate and fluoride additives on the disturbed calcium phosphate balance of the body, including caries, the experimentation was continued by varying the basal diet and the concentration of the additives. Addition of orthophosphate alone to a magnesium-deficient cariogenic diet strongly reduced fissure caries. This was accompanied by an appreciably reduced rate of growth. Phosphate addition per se also promoted both renal and aortic accumulation of calcium as well as accumulation of dental calculus. These undesirable effects of phosphate could be reduced or prevented by further addition of magnesium or fluoride or preferably by both simultaneously. All three additives together reduced fissure caries significantly. During low or medium basal dietary intake of magnesium, the fluoride, when fed with phosphate, reduced caries significantly too, but this could not fully correct phosphate-induced renal calcium accumulation. The additional presence of magnesium was necessary for the full correction of the renal calcium content. Aortic calcium was increased by phosphate in magnesium-deficient rats but it was corrected by fluoride. Phosphate-induced dental calculus accumulation was reduced by fluoride and magnesium together on a high-magnesium basal diet. The results suggests a possibility of preventing the mineral disequilibrium of the body, i. e. demineralization of hard tissues and mineralization of soft tissues through some simple alterations in food composition.

ISSN:0008-6568    

DOI:10.1159/000260256

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260257

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260258

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000260259

出版商:S. Karger AG    

年代:1977

数据来源: Karger