Sweet preference is higher in childhood than adulthood but the mechanism for this developmental shift is not known. The objective of this study was to assess perceptual, physiological and eating habit differences between children preferring solutions high in sugar (high preference) and children preferring solutions low in sugar (low preference). We tested 143 children (11-to 15-years old) using sip and spit methodology to assess their hedonic profile, detection threshold, and perceived intensity of sucrose. Their plasma concentration of several hormones, a biomarker of bone-growth, body size, puberty stage, and dietary habits were measured. Eighty-eight children were classified as high preference and 53 were classified as low preference based on their hedonic ratings to a series of sucrose solutions. A marker of bone growth measured in urine and plasma leptin adjusted for body weight were significantly lower in the low preference group. Children with high and low preference patterns did not differ in sensory aspects of sucrose perception, nor did they differ in age, body mass index percentile, or dietary restraint. The change in sugar preference from high to low during adolescence appears to be associated with the cessation of growth.

The objective of the present study was to study the supra- and subgingival microflora by culture and cDNA probe methods in 20 elderly subjects who were between 62 and 93 years of age. 10 of them had gingivitis only, and 10 had periodontitis. B. forsythus (BF), P. gingivalis (PG), P. intermedia (PI), P. nigrescens (PN), A. actinomycetemcomitans (AA), T. denticola (TD), and pathogen-related oral spirochetes (PROS) were studied. Oral hygiene was similar and poor in both groups. The mean probing depth at sample sites was 6.7 mm (S.D+/-1.3) in the periodontitis group and 2.2 mm (S.D.+/-1.5) in the gingivitis group (F=17.75, p<0.001). Mean clinical attachment levels (CAL) were 4.3 mm (S.D.+/-2.0) and 1.7 mm (S.D.+/-0.9) respectively (p<0.001). Total viable counts >1.0x10(5) in supra-gingival plaque samples were found in all periodontitis and in eight gingivitis subjects. 70x more black-pigmented organisms were found in supra-gingival and 185 times more in sub-gingival plaque from the periodontitis group (p<0.01). Culture data showed P. nigresecens in 10% periodontitis and 50% gingivitis subjects (p<0.03). In supra-gingival samples by the Affirm DP test, BF was present in 50% periodontitis and 60% gingivitis while culture data were negative for all subjects. PG was found in 30% periodontitis and 50% gingivitis subjects with TD in 70% periodontitis and in 30% gingivitis subjects. In the sub-gingival plaque samples 80% periodontitis and 70% gingivitis subjects had >1x10(5) anaerobes. The total count of black-pigmented organisms was significantly greater in the periodontitis elders (p<0.001). cDNA probes by the Affirm DP test identified subgingival presence of BF (80%) PG (80%), PI (80%), AA (0%), TD (50%) in periodontitis subjects with BF (70%), PG (40%), PI (30%) and TD (20%) in gingivitis subjects. PROS were found in (80%) samples from periodontitis and in (60%) of gingivitis elderly. Only the quantities of PI (r=0.48, p<0.01) and TD (r=0.37, p<0.01) were associated with the disease definition. The smoking habit in the periodontitis group was significantly higher (p<0.01). A history of smoking may contribute significantly to periodontitis in the presence of pathogens.

The results of the present study suggest genotype variation of B. forsythus that is unique to the individual and that serotype variation can be expected. It is possible that B. forsythus under specific host conditions can modulate surface antigen factors to evade the host immune response.

The relationship between granule density, protein content, and Ca and S contents were studied in two secretory granule fractions, from parotid glands of the rat, previously shown to constitute different stages in granule maturation. The density of the lighter fraction was between 1.133 and 1.142 g/ml, while that of the heavier fraction was greater than 1.142 g/ml. The mean protein content of the denser granules was 12% greater than that of the lighter granules (P less than 0.03), while the dry-mass elemental concentrations in the two granule fractions were unchanged. These results indicate that protein is added to granules during the maturation process (presumably by vesicular traffic), and that the resulting increase in granule density is not driven simply by decrease in water content and/or increased concentrations of inorganic Ca or S in the granules. The elemental concentration values also indicate that the diffusible elements permeate the granule membrane during the fractionation procedures.