摘要:

A micromodification of Somogyi’s starch-iodine colour method for determination of α-amylase in media from salivary gland tissue cultures, as well as homogenates of such tissues and in saliva, is described. The method was based on photometric determination of the starch-iodine colour changes during enzymic degradation of starch substrate at wavelengths 550 or 610 nm. No additional, apparently amylolytic effect, such as seen in serum, was observed by addition to the samples of 1 mg/ml of albumin and globulin, or about 1 mg/ml of proteins from homogenate of spleen. The test allows a reproducible and rapid way of calculating arbitrary units of α-amyl

ISSN:0008-6568    

DOI:10.1159/000259641

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Homogenization of salivary gland tissue from the Macaca irus monkey showed an α-amylase content/g wet weight of parotid tissue about five times that of submandibular tissue. The sublingual gland showed little or no amylase activity. When total size of the glands were considered, 93–95 % of the salivary amylase seemed to be produced in the parotid glands. The results after homogenization of human autopsy material and glandular tissue extirpated after parotid surgery indicated a similar distribution of salivary α-amylase. The Cercopithecus aethiops monkey showed similar concentrations of parotid amylase, but an inverse relationship was found between the content of amylase in the submandibular and the sublingual gland, as compared with that of the Macaca mon

ISSN:0008-6568    

DOI:10.1159/000259642

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

A new proportional counter technique for the assessment of mineral content of calcified tissues has been reported and its application to an understanding of enamel structure and dental caries in deciduous enamel was assessed. The pattern of caries in deciduous and permanent teeth has been compared and an explanation for the differences observed is offered in terms of structural differences in the enamel. The level of mineralization in postnatal and prenatal enamel was noted and it was found that the prenatal enamel was less mineralized than the postnatal enamel. The possible significance of these findings in the spread of dental caries is considered in the discussion.

ISSN:0008-6568    

DOI:10.1159/000259643

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Radiographs were taken of 580 unfilled approximal surfaces of all types of extracted permanent teeth with small carious lesions. The reproducibility of radiographic scoring was studied. More lesions were detected by inspection than on radiographs. Cavities were found in 34% of surfaces with radiolucencies limited to the outer enamel and in 66% when the radiolucent area had reached the inner half of the enamel. In surfaces with radiolucent areas involving the outer half of the dentine, cavities were found in 87% of the cases. The inciso-apical extent of lesions and the intensity of brown discoloration increased with increasing depth of lesion, but no such relationship was found for the bucco-lingual extent which seemed to depend on the bucco-lingual width of the teeth. Sections (3 mm wide), prepared from 24 surfaces with small lesions, revealed only 10 small lesions imperceptible on the radiograph before sectioning. The findings are compared with the results of other investigations.

ISSN:0008-6568    

DOI:10.1159/000259644

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

A method using an Orion combination electrode (96–09) was developed for determining the total fluoride content of soft tooth deposits. The samples were collected by plastic sealers and dried at 105° C. After weighing, the sample was dissolved in a small polypropylene tube, positioned inside a larger tube. The dissolution was carried out in 0.2 ml of a mixture of HClO4 and HNO3 at 60° C for 2 h. The outer tube contained 0.3 ml NaOH and 1 ml Na3-citrate. After the soft deposit was dissolved, the contents of the tubes were mixed without opening the sealed outer tube. The final mixture had a pH of 5.8 and the F–– was determined directly. The recovery was found to be satisfactory. Known amounts of F added to dried deposits of Streptococcus salivarius and to Ca3(PO4)2 indicated no F- binding in the solubilized material. Deposits collected from a group of children 5–6 days after mouthrinsing with 0.2 % NaF had an average fluoride concentration of 85 ppm F (on dry weight) as compared to 52 ppm F in the cont

ISSN:0008-6568    

DOI:10.1159/000259645

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Dentifrices containing fluoride and monofluorophosphate are possible sources of intake of fluorine compounds by humans, particularly young children. The purpose of the present study was to find the amount of monofluorophosphate toothpaste swallowed by children, utilizing the urinary excretion of fluoride as a marker, and to determine the fate of ingested monofluorophosphate. One hundred and five preschool children in Edinburgh, an area of low natural fluoride, were given a placebo paste to use for a week. A monofluorophosphate paste was then used for two weeks followed by a return to the placebo paste for a further week. Two 24-hour urine samples were collected from each child during each of the four weeks. The amounts of fluoride excreted were related to intake by determining the excreted proportion of a known dose. On average only 20 % of the fluorine was excreted in the urine. Ninety percent of the children swallowed less than 0.5 g of paste per day and only 7% of the children swallowed between 1 g and 2 g on any of the sampled days. This did not occur regularly with any of the children.

ISSN:0008-6568    

DOI:10.1159/000259678

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The object of this study was primarily to test the possible caries inhibiting effect of hexafluorostannate on human dentine. By employing the gold plate technique it was also intended to establish the feasibility of this method for studying dentinal caries. By means of grinding, the greater part of the buccal enamel was removed from seven premolars in situ. One half of the experimental area, consisting of abraded enamel and dentine, was given a 5 min topical application of sodium hexafluorostannate, having an initial fluoride concentration of 0.3 m and a pH of 2.35. Caries was induced for 16 to 20 days prior to extraction. The teeth were inspected in a dissecting microscope, photographed, sectioned, and subjected to microradiography. In most specimens a distinct difference was observed between the test and the control area, suggesting a caries protective effect of the solution in the dentine as well as in the enamel. These observations were confirmed by microradiography, which showed subsurface demineralization with a relatively well preserved surface layer. The demineralization revealed a pattern corresponding to dentinal tubules. Apparently the spread of the lesion was unaffected by the presence of interglobular spaces.

ISSN:0008-6568    

DOI:10.1159/000259679

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Fluoride uptake by the surface of rat molars was studied in vivo. Mature rats were selected in order to minimize endogenous fluoride supply to the tooth surfaces through the dentin via the dental pulp and were divided into 4 equal groups. One group was sacrificed at the start of the experiment and served as a base line. The three remaining groups were fed a low fluoride diet, with and without a daily dose of 0.167 mg F injected intraperitoneally as NaF, and a standard animal house diet, respectively. Six weeks from the beginning of the experiment all the rats were sacrificed. The surfaces of the mandibular and maxillary molar teeth were exposed to 0.2 N HCl for 30 min for removal of surface substance to be analyzed for fluoride. The surface layers were similar in thickness and weight in each group. A significant uptake of fluoride by the tooth surfaces occurred only in the group which received fluoride intraperitoneally. Low and normal fluoride intake, over a relatively short life period, did not appreciably increase the fluoride concentration of the molar teeth surfaces in mature rats.

ISSN:0008-6568    

DOI:10.1159/000259680

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000259681

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000259682

出版商:S. Karger AG    

年代:1970

数据来源: Karger