Antibacterial activity against periodontopathic bacteria was measured for metronidazole (MTZ), amoxycillin (AMPC), and ofloxacin (OFLX), and the effect of combined use of these antibacterial agents was examined on the activity. MTZ showed strong activity againstP.g., P.i, andP.n., while it had weak activity againstA.a. AMPC was strongly active againstA.a. andP.g., whereas some strains ofP.i. andP.n. were resistant to the agent. OFLX exhibited the highest activity against A.a. among the three agents. Combined uses of MTZ and OFLX, AMPC and OFLX gave an broad antibacterial spectrum that is effective against all the strains studied.
Since periodontopathic bacteria are widely varied, combined use of different antibacterial agents would have high antibacterial activity for many types of bacteria.

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Platelet-rich plasma (PRP), separated by centrifugation of autologous blood, is a plasma containing numerous platelets. Consequently, efficient separation of PRP can provide highly concentrated autologous growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), and insulin-like growth factor-I (IGF-I), derived from α granules. However, it requires a substance to trigger platelet aggregation, in order to activate platelets to release the growth factors.
In the present study, we investigated a procedure of activating platelets (aggregation) with calcium chloride alone, in the absence of thrombin, the safety of which is suspected. Prior to the investigation, we sought the optimal centrifugal conditions, i.e., centrifugal gravity and time, for separation of PRP. As a result, we discovered that a centrifugal gravity of 130 (×g) and a centrifugal time of 10 min, are the optimal conditions for separating PRP. The time required for platelet aggregation was prolonged in platelet activation by calcium chloride alone, as compared with platelet activation by thrombin. However, activation of platelets with calcium chloride alone demonstrated gelatinization of PRP indicative of sufficient fibrin formation.

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Rb protein (pRb) expression and its genetic mutations have been reported in many carcinomas. However, little is known about the relation between pRb phosphorylation and the clinical characteristics of tumors. In this study, we examined Rb protein (pRb) expression and phosphorylation in oral carcinoma specimens. Twenty-six oral carcinoma specimens were immunoprecipitated with anti-Rb antibody and then subjected to Western blotting with antibodies against phosphorylated pRb (Thr373, Ser780, and Ser807/811) . Data were analyzed with a densitometer. Thirteen of 26 specimens (50%) expressed pRb, whereas 13 of 26 (50%) lost pRb. All 6 control specimens expressed pRb. pRb in the control group was unphosphorylated, in contrast to pRb in tumor samples, which was frequently phosphorylated at all sites [Thr373: 7/13 (54%), Ser780: 9/13 (69%), and Ser807/811 12/13 (92%) ] . The extent of phosphorylation tended to increase from T1 to T4 at all phosphorylation sites. The majority of pRb-deficient or hyperphosphorylated samples (inactive group) contained tumors [Thr373: 20/26 (77%), Ser780: 22/26 (85%), and Ser807/811: 25/26 (96%) ] unlike pRb-expressing or hypophosphorylated specimens (active group) . There was a significant difference between controls and the tumor group, but not among the different tumor categories. These results suggest that pRb expression and phosphorylation are important indicators of pRb function. pRb inactivation occurred in the early stages of tumorigenesis, but not during progression of tumor.

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An osteoblastic cell line: MC3T3-E1, forms mineralized tissues during cell culture with increased alkaline phosphatase (ALP) activity. Addition of phosphatidylinositol-specific phospholipase C (PIPLC) to culture medium released membranebound ALP and highly increased ALP activity in the medium, compared to naturally released ALP without PIPLC. Continuous treatment with PIPLC did not affect mineralization of MC3T3-E1 cells, but treatment for only 2 hours every 3 days increased mineralizaiton at its late stage. We suspect that these results were not caused by activation of released ALP or increased ALP mRNA by the PIPLC treatment. These results suggest that embedded ALP was exposed by release of membrane-bound ALP, and that the newly exposed ALP was important for mineralization of the cells.

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Our previous survey on off-label drug use in oral therapeutics and pharmacology, showed that amphotericin B syrup had been used to treat adult oral candidiasis in many hospitals. Based on the results, we studied how antifungal drugs were used for oral candidiasis in university dental hospitals, and searched for evidence of appropriate use of amphotericin B syrup for the treatment.
According to a questionnaire we conducted at 18 private dental college and university hospitals, miconazol gel and amphotericin B syrup were used in 15 and 13 hospitals, respectively. However, amphotericin B syrup occupied 2/3 of the total amount of anti-fungal drugs used in the 18 hospitals. Two different administration methods were observed: one method in which the preparation was swished in the mouth and then swallowed (in 4 hospitals), and the other in which it was gargled (in 9 hospitals) . Evidence of appropriate dosage and administration for both methods was searched in a computer database of Igakuchuoh Zasshi-CD-ROM, but there was only one literature about the gargle. There was another literature about swishing in the mouth, offered by the manufacturer. These two literatures were case reports and were considered to correspond with level III in AHCPR grading scale. Then we searched in PDR for higher evidence, and found a description that 1 mL of amphotericin B syrup was dropped onto the tongue and swished in the mouth before swallowing.

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