Five years of community preventive dentistry and health education in the county of Sutherland, Scotland.

Examination of 11-year-old Scots children who had participated in a 5-year, fortnightly dental health education and preventive dentistry programme showed that, compared with a similar age-matched group, the regimen produced mean DMF and DMFS reductions of 48.6% and 42.1%, respectively. In addition, the plaque and gingival indices differed significantly and 22.5% of test children were caries-free compared with only 7.6% of controls.

Nerve growth factor determines survival and death of PC12 cells by regulation of the bcl-x, bax, and caspase-3 genes.

We investigated the effects of nerve growth factor (NGF) and NGF withdrawal on expression of members of the bcl-2 family of genes and caspase-3 in PC12 cells. NGF regulated several members of the bcl-2 family and caspase-3 in a manner consistent with its effect on apoptosis in PC12 cells. Levels of bcl-xl, bcl-xs, and caspase-3 mRNAs were increased by NGF treatment. The increases in caspase-3 and bcl-xs levels should have disposed the cells toward apoptosis but were opposed by the simultaneous increase in bcl-xl level. NGF withdrawal resulted in abrupt down-regulation of bcl-xl and up-regulation of bax, favoring apoptosis. Forced expression of bcl-xl after NGF withdrawal was sufficient to prevent cell death. Cell death was rapid when NGF was withdrawn after 5 days of treatment but relatively slow when NGF was withdrawn after only 1 or 2 days of treatment. This was consistent with the reduced accumulation of caspase-3 mRNA with shorter NGF treatments. These results indicate that Bcl-xl, Bcl-xs, Bax, and caspase-3 are important regulators of apoptosis in PC12 cells. Furthermore, regulation of their mRNA levels is implicated in the signal transduction of NGF.