Characterization and Antibacterial Effect of an Experimental Adhesive Containing Different Concentrations of Proanthocyanidin.

PURPOSE: To evaluate the degree of conversion (DC%), water sorption (Sp), solubility (Sl), dentin bond strength (µTBS) (immediate and after 12 months of storage), and the antibacterial effect of an experimental adhesive containing different concentrations (%) of proanthocyanidin (PA): 0, 1%, 2%, 4.5%, and 6% (PA0, PA1%, PA2%, PA4.5% and PA6%, respectively). MATERIALS AND METHODS: DC% was measured by FT-IR and the Sp and Sl were determined based on the ISO 4049 specification. For µTBS, resin composite buildups were constructed incrementally and specimens (n = 8) were sectioned to obtain sticks (1 mm2). The µTBS was evaluated after 24 h and 12 months of water storage at 37°C. The failure mode was analyzed. The antibacterial effects were evaluated by analyzing the bacterial growth (S. mutans) (n = 5) and antibiofilm activity (n = 5) of the adhesives by spectrophotometry. RESULTS: The incorporation of PA did not affect the Sp, Sl, or DC%. Immediate µTBS was similar for all groups. After 12 months, PA4.5% presented significantly higher µTBS than PA0, while the other groups did not differ from PA0 and PA4.5%. Groups PA0 and PA1% underwent significant reduction in µTBS. In the experimental groups PA2%, PA4.5% and PA6%, µTBS was maintained after storage. All groups showed antibacterial activity. CONCLUSION: Incorporation of 2%, 4.5%, and 6% PA maintained the dentin µTBS after 12-month storage, without affecting the Sp, Sl, or DC% of experimental adhesives. PA4.5% presented higher µTBS values than PA0 after 12 months. The adhesive presented antibacterial effect irrespective of PA concentration.

Effects of Repeated Treatment with Midazolam in SHR and SLA16 Rat Strains in the Triple Test.

We exposed male and female rats of SHR (Spontaneously Hypertensive Rats) and SLA16 (SHR.LEW-Anxrr16) strains, in a non-drugged state, for five consecutive days to the Triple Test (experiment 1); or after repeated treatment with midazolam (MDZ), for four consecutive days. The fifth day was performed without treatment (experiment 2). The first experiment showed that males did not avoid and females increased the exploration of the open arms over the days. In experiment 2, SLA16 from both sexes approached more the open arms than SHR rats. The MDZ anxiolytic-like effect was sustained in both strains and sexes over the days. On the fifth day, SLA16 still approached more the open arms than SHR rats. Data suggest an absence of repeated-trial tolerance to MDZ anxiolytic-like effects. Testing the SHR and SLA16 strains, especially females, could be necessary for the future search for the genes and molecular pathways underlying anxiety/emotionality.

Statins enhance cognitive performance in object location test in albino Swiss mice: involvement of beta-adrenoceptors.

Statins are inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, thereby inhibiting cell synthesis of cholesterol and isoprenoids. Moreover, several studies have been evaluating pleiotropic effects of statins, mainly because they present neuroprotective effects in various pathological conditions. However, knowledge about behavioral effects of statins per se is relatively scarce. Considering these facts, we aimed to analyze behavioral responses of atorvastatin or simvastatin-treated mice in the open field test, elevated plus maze and object location test. Atorvastatin treatment for 7 consecutive days at 1 mg/kg or 10 mg/kg (v.o.) or simvastatin 10 mg/kg or 20 mg/kg enhanced cognitive performance in object location test when compared to control group (saline-treated mice). Simvastatin effects on mice performance in the object location test was abolished by post-training infusion of the beta-adrenoceptor antagonist propranolol. Atorvastatin and simvastatin did not change the behavioral response in open field and elevated plus-maze (EPM) tests in any of the used doses. These data demonstrate the positive effects of both statins in cognitive processes in mice, without any alteration in locomotor parameters in the open field test or anxiolytic-like behavior in EPM. In conclusion, we demonstrate that atorvastatin and simvastatin per se improve the cognitive performance in a rodent model of spatial memory and this effect is related to beta-adrenergic receptors modulation.