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Biomedical subjects

M M Dolan

Publications and source records attributed to M M Dolan.

At least 19 recordsLinked to original sources

C31G, a new agent for oral use with potent antimicrobial and antiadherence properties.

C31G, an equimolar mixture of alkyl dimethyl glycine and alkyl dimethyl amine oxide, was evaluated for antimicrobial and antiadherence properties. The efficacy of C31G, its two components, and several commercial mouth rinses was determined in assays measuring inhibition of glycolysis, inhibition of bacterial adherence, and MICs. Inhibition of glycolysis was determined by using a saliva sediment model, with glycolytic activity expressed as the change in pH relative to that of a control. Adherence studies were undertaken with Streptococcus sobrinus 6715 to measure inhibition of adherence to nichrome wires. MICs were determined against selected microorganisms by standard methods. C31G demonstrated broad-spectrum antimicrobial properties, with activity against both gram-positive and gram-negative organisms and Candida albicans, a yeast. C31G inhibited both glycolysis by salivary bacteria and adherence of Streptococcus strains to wire mesh. C31G was more effective in the assays conducted than any commercial formulation tested and was as effective as chlorhexidine. A synergistic effect was demonstrated between the individual components of C31G, and no loss of activity was noted when it was formulated into a mouth rinse vehicle.

Anti-Bacterial Agents

Comparison of effects of two dosage regimens of phenylpropanolamine on blood pressure and plasma levels in normal subjects under steady-state conditions.

Plasma levels and blood pressure responses to two dosage regimens of phenylpropanolamine (PPA)-25-mg, immediate-release tablets three times per day and a 75-mg, controlled-release capsule once per day--were compared in 14 normal subjects. To obtain steady-state conditions, subjects were given the test materials for four-day periods, and blood pressure and plasma PPA levels were measured on day 4. The dosage forms were equally bioavailable, based on a 95-percent confidence coefficient, and neither produced hypertensive effects. The highest diastolic pressure was 96 mm Hg three hours after a 25-mg dose. Mean PPA plasma levels showed no correlation with mean blood pressure readings at any point during a 12-hour test period. These data show that, in these subjects, a daily dosage of PPA 75 mg, either in divided doses of 25 mg each or in a dependable controlled-release formula, produces no indication of pressor effects.

Administration, Oral

In vitro method for evaluation of spermicides by hemolytic potency.

Nonoxynol-9 immobilizes sperm and hemolyzes erythrocytes at analogous concentrations; therefore, erythrocytes may be utilized for predicting in vitro spermicidal potency. Since erythrocytes (human or rabbit) are usually more readily available in larger quantities than are spermatozoa, this method permits extensive in vitro testing of different formulations of vaginal spermicides.

Animals

Anticalculus and antiplaque activity of 8-hydroxyquinoline sulfate.

The effect of 8-hydroxyquinoline sulfate on the formation of artificial calculi, rat calculus, and dog plaque plus its ability to remove dog plaque were studied. Several chemically related agents were also evaluated for their anticalculus effects. The most effective anticalculus agent was 8-hydroxyquinoline sulfate. At concentrations of 4 or 5%, swabbed over molar teeth, it was essentially equally effective in retarding the formation of rat calculus. Significant (1% level) reduction occurred with concentration as low as 3% in rats. When used so as to mimic mouthrinse use, 4% 8-hydroxyquinoline sulfate also significantly (5% level) reduced formation of calculus in rats. All rats showed normal behavioral and weight-gain patterns. Visual evaluation of oral tissues in the swabbing tests plus visual and histopathological evaluation of oral tissues in the mouthrinse procedure showed 8-hydroxyquinoline sulfate had no irritating or toxic effects. In dogs, the teeth treated with 4% 8-hydroxyquinoline sulfate nine times during a five-day period had 93.7 to 98.4% less buccal plaque than vehicle-treated teeth. The antiplaque effect was considerable in both canines and fourth premolars. In older dogs, teeth treated with 4% 8-hydroxyquinoline sulfate 15 times during a ten-day period had 33 to 46.1% less plaque than when treated with the vehicle. The effect was considerable on canines but slight on fourth premolars. In older dogs after 24 treatments during a 15-day period, 4% 8-hydroxyquinoline sulfate removed 25 to 57.5% of established plaque whereas the vehicle removed 2.5 to 22.5%. Again, 8-hydroxyquinoline sulfate was more effective on canine buccal plaque. These results show that 8-hydroxyquinoline sulfate is an effective anticalculus and antiplaque agent that is nontoxic to animal oral tissue. The results also indicate that the dog is a suitable animal model for the evaluation of antiplaque agents.

Animals