Human plasma containing IgM showed only minimal, if any, reactivity with a panel of antigens as measured by ELISA. In contrast, affinity-purified IgM showed many times more reactivity with the same panel of antigens. When plasma was added back to the affinity-purified IgM, the reactivity of the IgM with antigens was completely inhibited by undiluted plasma and by as much as 40% with as little as a 1:100 dilution of plasma. When the affinity-purified IgM was affinity-purified a second time by passage through antigen-specific columns (e.g., insulin or Fc or beta-galactosidase), the eluted antibodies bound not only to the antigen used for purification, but also to a panel of unrelated antigens, indicating that the antibodies were polyreactive. It is concluded that polyreactive IgM antibodies are present in the circulation but are masked by binding to circulating antigens.

No abstract

The effect of copper sulfate applied topically or in drinking water on dental caries was investigated in rats. Two daily topical applications of 0.2 ml of 5.0 mM Cu²⁺ as CuSO₄ ad libitum or 1.0 mM CuSO₄ in the drinking water reduced the caries scores significantly on all tooth surfaces. The number of Streptococcus mutans colonising tooth surfaces was also significantly reduced by 1.0 mM Cu²⁺ in drinking water.

Fewer smooth surface carious lesions developed in rats fed a high-sucrose diet (2000) administered by a feeding machine delivering 22 portions (‘meals’) per day when additional meals of cheese (‘snacks’) were consumed after 12 selected meals. Snacks of peanuts had less effect. Further meals of diet 2000 instead of cheese or peanuts increased caries in smooth surfaces and fissures. Streptococcus mutans, inoculated at the start of the experiment, was recovered at significantly lower levels in the animals receiving cheese than in the groups receiving additional diet 2000 or no additional snacks. Salivary gland weights of all three groups fed supplementary meals were raised, but pilocarpine-stimulated saliva flow rates were increased only in the cheese and peanut groups. The results with cheese confirm expectations based on earlier studies of plaque pH changes in human subjects but the lack of effect of peanuts requires further study.

A cariostatic effect of copper sulfate was observed in rats in a recent study by Afseth et al. In the present study, effects of the combination of topically applied copper with fluoride in the drinking water were determined. Groups of animals receiving a combination of copper and fluoride developed significantly less caries than the groups given either substance alone at the corresponding concentrations. Reduced numbers of Streptococcus mutans were isolated from animals receiving Cu treatment. This reduction was most pronounced in rats treated with elevated Cu concentrations alone and in combination with F.

This investigation measured the effect of two agents: CK 0569 A (a piperazine derivative) and octenidine on dental caries and plaque when used as oral rinses in rats. Twice daily flushings with aqueous solutions of either agent (0.5%) provided significant protection against dental caries and plaque, similar to that provided by chlorhexidine, when compared to the effects of the placebo rinses. However, when flushings (1.0%) were provided only once daily, only the octenidine-treated group exhibited a mean caries score that was significantly lower than that in the placebo-treated group. Animals receiving oral flushings once daily with octenidine (1.0%) in an oral flushing vehicle exhibited a 37% numerical decrease (0.1 > p > 0.05) in plaque scores compared with the animals treated with the carrier solution without additive.

Rats treated continuously with topical fluoride from an intraoral delivery system (Intraoral Fluoride-Releasing Device) developed significantly fewer proximal, sulcal, and total carious enamel areas after 5 weeks on a caries-conducive regimen than did rats that received fluoride at a similar rate systemically from a subcutaneously implanted controlled-release delivery system. Rats treated with continual topical fluoride or with intermittent topical fluoride from drinking water had significantly fewer carious enamel areas on third-molar surfaces than rats treated with continual systemic fluoride. The findings suggest that the substantial cariostatic benefits produced by the intraoral fluoride-releasing device in rat caries trials were the result of topical effects due to the continual presence of fluoride in the oral fluids.

No abstract