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Biomedical subjects

S L Yue

Publications and source records attributed to S L Yue.

16 recordsLinked to original sources
PubMed1997

[Calcium ion-selective miroelectrodes for measurement of free calcium in saliva]

In this paper, the free calcium concentration in saliva was measured and evaluated by the neutral carries ion-selective microelectrodes.The statistical results showed that there was no significant difference (the groups of all,P>0.05) between children and adult,between male children and female one,between caries-free and caries-active,and between interval of two weeks.The results suggested that caries might be no direct relation to the calcium concentration in children physiological saliva. Calcium ion-selective microelectrodes seems to be a good method for measuring free calcium in oral micro-sample fluid.

Journal Article↗
PubMed1993

[Proteolytic phenomenon in enamel caries]

The proteolytic phenomenon in enamel caries has been investigated from three directions.Three kinds of proteolytic enzymes,papain,trypsin and collagenase have been used for treating enamel both in vitro and in vivo to observe their effect on the development of artificial enamel caries and demineralization of upper central incisors of thirty young persons.The results showed that the depth of the artificial caries was not increased after enzyme treatment.The calcium content of the demineralizing solution is also not increased after enzyme treatment.when the enamel powder of human beings was treated at first by natural plaque fluid and then by demineralizing liquid,no difference was observed between the data of experimental and control groups.Therefore,the results of this study does not support Gottleib's proteolytid theory of caries,especially in case of enamel ones.

Journal Article↗
PubMed1992

Multibacterial artificial plaque. A model for studying carious process.

A multibacterial artificial plaque was established in vitro on enamel slabs incubated in mixed culture of Streptococcus sanguis, Streptococcus mutans (serotype c), Streptococcus salivarius, Lactobacillus casei and Actinomyces viscosus. Typical structure same as natural plaque was seen under microscope. The caries-like lesion produced under the plaque was observed in enamel sections. The lesion was similar in appearance to natural ones under optic and scanning electron microscopes. The acids produced in both culture media and artificial plaque were similar in composition and type to those produced in natural plaque after sugar attack. It is suggested that this kind of plaque model may be useful in studying carious process in vitro, because it is easily controlled either by changing the composition of bacteria or by adding different kinds of nutrient in the media. Moreover, the results will be easier to explain than those produced in natural ones.

Dental Caries↗
PubMed1989

Dynamic analysis of organic acids in extracellular fluids of human dental plaques.

Organic acids in unstimulated saliva and extracellular fluids of dental plaques from 12 middle school students were measured by ion-chromatography. The acids in the plaques were analyzed before and 5-10, 30-35, 60-65 minutes after rinsing with 10% sucrose solution. The differences of the acids between the extracellular fluids of resting plaques and unstimulated saliva were significant. In the extracellular fluids of plaques, the concentration of high pK acids, i.e. acetic and propionic acids was higher than that of low pK acids i.e., lactic and formic acids before and after sucrose rinse. The relations of time-dependent changes between the ratio of low pK to high pK acids and pH were observed in the extracellular fluids of plaques after sucrose rinse. No significant difference of lactic acid concentrations was found between the caries-active and caries-free subjects 30-35 minutes after sugar rinse. The concentration of acetic acid was much higher in the extracellular fluids of dental plaque at any time. It is suggested that there may be some relationship between acetic acid and caries process.

Acetates↗