Bone tissue reactions to EBA, IRM, and cyanoacrylate cement (Base Liner) were studied in the rat mandible using an intraosseous implant method. Osseous cavities (1.4 mm in diameter) were surgically created in the mandibles, and materials were implanted in 60 male Wistar rats. Each specimen was evaluated histologically after 4 and 8 weeks. The development of fibrous connective tissue in direct apposition to the material was observed in the EBA and IRM groups at 4 weeks. A slight degree of macrophage infiltration was seen in the EBA group. After the 8-week observation period, IRM and EBA were frequently separated from the bone cavity by a fibrous connective tissue layer (p<0.01). The Base Liner appeared to be in direct apposition to the osseous tissue in several areas (p<0.01). These findings indicate that Base Liner reacts favorably with osseous tissue, compared with the EBA and IRM materials tested and seems to be a biocompatible material.

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The purpose of the present study was to investigate whether the use of a chitosan mouthrinse could be efficacious in reducing plaque and saliva mutans streptococci level. A randomized crossover clinical trial was performed to evaluate the effect of a rinse with 0.5% chitosan for 14 days on plaque formation and mutans streptococci counts in saliva. Twenty-four subjects were randomly assigned either the chitosan rinse or a placebo rinse in addition to their usual oral hygiene procedures. Following the baseline examination, each subject was given a prophylaxis. They were instructed to rinse with 20 ml of the mouthrinse twice daily for 30 seconds. Plaque scores were measured after a 14-day rinsing period, and mutans streptococci counts in saliva were also determined at the start and the end of the each rinsing period. The procedures were repeated with the alternate rinse after a 14-day washout period. Rinsing with 0.5% chitosan was significantly more effective in plaque reduction using the Quigley & Hein Index (chitosan: 1.44, placebo: 1.62, p<0.001) and Plaque Severity Index (chitosan: 0.138, placebo: 0.186, p=0.003). The mutans streptococci count in saliva was less after the chitosan rinsing ( χ²_cal=13.51, p=0.035) than placebo rinsing. In conclusion, the chitosan rinsing was effective in reducing plaque formation and counts of salivary mutans streptococci after a 14-day rinsing period. These results would appear to warrant further investigation into the potential value of chitosan as an effective anti-plaque agent for use in oral hygiene products.

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An 11-year-old male was admitted because of frequent vomiting and truncal ataxia which had lasted for over one week. He had clear consciousness but slowly-progressive mild headache and ataxic gait. Cranial CT revealed a 4 cm hematoma in the right cerebellar hemisphere. Angiography showed a 2×2 cm nidus of a pial arteriovenous malformation (AVM) in the right hemisphere fed from the right posterior inferior cerebellar artery and draining into the inferior hemispheric vein. We performed a surgical resection of the AVM after decompression therapy to counteract the brain edema. He recovered completely without any neurological deficits. This case suggests that cerebellar hemorrhage caused by AVM should be considered as a possible diagnosis when mild symptoms of headache and ataxia proceed gradually.

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In this study, we have investigated the effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on in vitro hamster submandibular ganglion neurons using the conventional intracellular recording technique. PACAP (10 μM) induced slow depolarizations in approximately 70% of tested cells. PACAP-induced depolarizations were approximately 10mV in the peak amplitude, and their durations were approximately 10 min. The slow depolarizations were accompanied by a decrease in membrane conductance (gm) at the initial phase and an increase in gm at the peak phase. Membrane input resistance increased by 14.8±2.2% (mean±S.E., max.) of the resting value at the initial phase and decreased by 30.8±4.3% (max.) at the peak phase. Anodal break spikes were elicited at the initial phase during PACAP-induced depolarization. In one neuron, anodal break spikes were elicited at the peak. Spikes which followed the anodal break spike were also elicited at 4Hz in the initial phase during the slow depolarizations. The decrease in gm was probably produced by an inhibition of calcium conductance and an inhibition of slow Ca²⁺-activated K⁺ channels, while the increase in gm might have been produced by an activation of nonselective cation channels. The slow depolarizations by PACAP might be mediated by a membrane-delimited signal transduction cascade involving G protein in the submandibular ganglion neurons.

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