摘要:

Fifteen of twenty strains of Streptococcus sanguis have been grown in a chemically defined medium. The requirement of organic compounds for one of the strains was: arginine, cysteine, glutamic acid, leucine, methionine, valine, adenine, biotin, thiamine, riboflavin, pyridoxine, pantothenic acid, nicotinic acid and glucose.

ISSN:0008-6568    

DOI:10.1159/000259652

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Ten strains of Streptococcus mutans, representing four serological groups, have been grown in chemically defined media. For anaerobic growth, one of the strains required the following organic compounds: glucose, cysteine (or thioglycolic acid), biotin, p-aminobenzoic acid, thiamine, riboflavin, pyridoxine, pantothenic acid and nicotinic acid. Except for this vitamin requirement, the organism could use ammonia as the sole source of nitrogen for growth. In aerobic culture, uracil and one of the amino acids, glutamine, glutamic acid, asparagine or aspartic acid, had to be included in the medium for growth of the organism.

ISSN:0008-6568    

DOI:10.1159/000259653

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Fluoride concentrations were determined in saliva from children and young adults by means of a fluoride ion electrode (Orion Research Inc.). Children who consumed drinking water containing 1 ppm fluoride (Group 1) showed a mean fluoride concentration of 0.009 ppm in parotid saliva. Children residing in a community with less than 0.1 ppm fluoride in the drinking water (Group 2) showed a mean concentration of 0.007 ppm. The comparable mean concentration was 0.008 ppm in children from the same community receiving a daily supplement of 1 mg fluoride (Group 3) while adults from a non-fluoridated community who refrained from the use of fluoride dentifrices for one week (Group 4) had a mean concentration of 0.010 ppm in parotid saliva. It was further found that simultaneously collected stimulated parotid and submaxillary saliva had identical concentrations on an individual basis. Fluoride concentrations were higher in whole saliva than in duct saliva from the same individual. The mean fluoride concentration in whole saliva in Group 1 was 0.033 ppm compared to 0.011, 0.015 and 0.017 ppm respectively in Groups 2, 3 and 4. The increased fluoride concentrations in whole saliva were attributed to inclusion of cellular debris and mucus since the concentrations decreased when whole saliva was ‘cleared’ by centrifugation. Also the fluoride concentration tended to decrease in a series of successively collected samples of whole saliva. Dental plaque and material scraped from the tongue contained significant amounts of fluor

ISSN:0008-6568    

DOI:10.1159/000259654

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Four per cent of the sucrose component of a cariogenic diet of the 580 type was replaced by a combination of Na2HPO4 + NaH2PO4 + KH2PO4 (mole ratios 4.65/0.52/1.00, respectively) or with NaHCO3 + KH2PO4 (mole ratio 9.82/1). The same combinations were also used to replace 4% of the sucrose component of the modified diet of the 2000 type. Osborne-Mendel rats were fed the former experimental and control diets and Sprague-Dawley rats the latter, for 60 days in each case. The alkali phosphate combination reduced caries more effectively than the bicarbonate-phosphate supplement. However, the former combination increased the formation of the dental calculus more than the latter. The alkali phosphate addition caused formation of renal calculi, especially in the former experiment, whilst no renal calcification was found in association with the bicarbonate-phosphate addition.

ISSN:0008-6568    

DOI:10.1159/000259655

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Three synthetic cariogenic diets containing either 25, 10 or 5% of casein with 52% sucrose were given to 3-week-old rats for either 1, 5, or 11 weeks. Stephan 580 cariogenic diet was also tested. Estimations were made of the haemoglobin concentration, packed cell volume, mean corpuscular haemoglobin concentration, and the erythrocyte count. Serum levels were determined for the total plasma protein, albumin, globulin, alkaline phosphatase and vitamin A. Anaemia and lowering of serum albumin, alkaline phosphatase and vitamin A occurred in the animals on low protein diets. Similar trends in haematological values were seen at the fast growing phase in rats on diets of ‘borderline adequacy’. Since it is possible that such changes in the blood may influence the formation and maturation of enamel in the rat, it was concluded that side effects should be prevented by ensuring that high sucrose cariogenic diets have an adequate protein-calorie ra

ISSN:0008-6568    

DOI:10.1159/000259656

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Streptococcus strain 1A, which closely resembled Streptococcus salivarius was isolated from human dental plaque. It was found to form gelatinous plaque deposits and to induce dental caries and alveolar bone loss in gnotobiotic rats fed a sucrose-containing diet. Animals fed diet 2000 developed primarily root and interproximal smooth surface lesions, whereas animals fed died 585 developed both fissure and root lesions. Histological examination revealed that the alveolar bone was severely resorbed, possibly due in part to hypervascularization of the bone. In vitro strain 1A formed plaque-like deposits in sucrose broth, but not in broth containing glucose, fructose, glucose and fructose, or maltose. Chemical, spectrophotometric and chromatographic analysis indicated that large quantities of levan and smaller amounts of glucose-containing polysaccharides were formed from sucrose. Synthesis of dextran-like polysaccharide rather than levan appeared essential for the development of plaque-like deposits, for no deposits developed in sucrose broth supplemented with dextranase, fructose or low MW dextran. Strain 1A formed fructosyl and glucosyl transferases constitutively, and the enzymes were present in a cell-free and cell-bound form. Preparations of the cell-associated fructosyl and glucosyl transferases were active from pH 4.5 to pH 8.0, with an optimum at approximately pH 6.0. Strain 1A did not synthesize iodophilic polysaccharide for nutrient storage, but was able to degrade levan, suggesting that levan may be utilized as a nutrient reserve.

ISSN:0008-6568    

DOI:10.1159/000259657

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000259658

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000259659

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000259660

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000259651

出版商:S. Karger AG    

年代:1970

数据来源: Karger