OBJECTIVETo evaluate the capability of quantitative light-induced fluorescence (QLF) for monitoring the remineralization of lesions lengthways and distinguishing the effect of different fluorides.

METHODSFollowing baseline early caries examination, 305 school students (age from 11 to 14 years old)were qualified from Chengdu area. The schools in which the subjects studied were randomized into three groups: NaF group, MFP group and nonfluoride group. The subjects of three groups brushed the teeth with 1450 mg/L sodium fluoride dentifrice, 1450 mg/L sodium monofluorophosphate dentifrice and non-fluoride dentifrice, respectively. QLF images of early lesions on smooth surfaces of the maxillary anterior teeth were taken at baseline, three and six months after the initiation of experiment. These images were analyzed by the trained examiner with the area of lesion (Area), fluorescence loss (deltaF) and gross fluorescence loss quantity (deltaQ).

RESULTS296 school students completed the study. After three months, the lesions on smooth surfaces got better in all three groups. The change of Area, deltaF and lg deltaQ amongst three groups had no statistical significance (P>0.05). After six months, the lesions on smooth surfaces also got better in all three groups than at baseline. The change of Area, deltaF and lg deltaQ of the lesions in NaF group and MFP group exhibited significant decreases than that of no-fluoride dentifrice group (P<0.05). But no significantly difference was found between NaF group and MFP group (P>0.05).

CONCLUSIONAs a diagnostic method which could quantify the miner content, QLF system has the capability of monitoring the variations of lesions lengthways.

Dentifrices ; Female ; Fluorescence ; Fluorides ; Humans ; Light ; Male ; Phosphates ; Sodium Fluoride

The full length cDNA of silkworm hibadh gene was cloned by RT-PCR and RACE (Rapid amplification of cDNA ends) technique. The hibadh gene and its deduced amino acid sequences were analyzed. The tissue distribution of hibadh gene in 5th instar silkworm larvae was tested by RT-PCR. The expression patterns of hibadh gene in simulated weightless environment were analyzed by real time RT-PCR. The results showed that the full length hibadh cDNA sequence was 1074 bp in lenth, including an open read frame of 969 bp encoding the entire coding region of Hibadh (GenBank accession No. EU719652). The deduced amino acid sequence similarities of hibadh between silkworm and Burkholderia ambifaria, Drosophila melanogaster, Apis mellifera, Xenopus tropicalis, Mus musculus, Homo sapiens were 46%, 43%, 48%, 44%, 45%, 45%, respectively. Signal peptide analysis showed that Hibadh was a secretory protein. There wasn't glycosyl-phosphatidyl inositol anchor site in Hibadh amino acid sequence. Molecular weight and isoelectric point of Hibadh were 34.1 kD and 9.14 respectively. The RT-PCR tests indicated that the hibadh gene expressed in head, silk gland, midgut, cuticle, blood, fat body, tuba malpighii of the 5th instar silkworm larvae. There were different expression patterns of hibadh gene during different silkworm embryo period in simulated weightless environment. Simulated weightlessness resulted in the expression of silkworm hibadh gene up regulated 2.3-fold (P < 0.05), up regulated 4.6-fold (P<0.01), down regulated 7.6-fold (P < 0.01), down regulated 2.6-fold (P < 0.05) during apophysis formation period, inverse period, trachea formation period, and whole embryo period, respectively. There was no significant change of hibadh gene expression during other period of silkworm embryo between simulated weightless and control groups. There were different response patterns to simulated weightless environment between hibadh gene and whole body of silkworm. Gene showed much higher sensitivity compared to whole body in response to environment. This study is useful for the further research on the gravity biological mechanism of hibadh gene.
Alcohol Oxidoreductases ; genetics ; metabolism ; Amino Acid Sequence ; Animals ; Base Sequence ; Bombyx ; enzymology ; genetics ; Cloning, Molecular ; Computer Simulation ; Genes, Insect ; genetics ; Models, Biological ; Molecular Sequence Data ; Weightlessness