Cefuroxime (CXM) concentrations in human serum, gingiva, mandibular bone, and dental follicle following a single oral administration of cefuroxime axetil (CXM-AX) (500mg) were studied. The mean concentrations in serum, gingiva, mandibular bone, and dental follicles peaked at identical times, 2 hours after administration, and were 5.60μg/mL, 2.02, 0.81, and 1.70μg/g, respectively. The mean concentration ratios of gingiva/serum, mandibular bone/serum, and dental follicles/serum at the peak time were 0.39, 0.16, and 0.34, respectively. Most of the CXM concentrations in gingiva, mandibular bone, and dental follicles exceeded the MIC for 90% of clinically isolated strains of oral streptococci. Thus, CXM-AX may be a valuable antimicrobial agent for the treatment of odontogenic infection.

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The rate of transient bacteremia at the time of tooth extraction using 300mg of cefditoren pivoxil (CDTR), an oral antimicrobial agent, on 56 patients needing tooth extraction was examined. As a result of the examination, 18 patients (32.1%) were positive and 23 strains were isolated. Fourteen strains out of 23 isolates were Streptococcus. The MICs of CDTR were ≤0.025 to>100μg/mL. The serum concentrations of CDTR were also measured, and varied from ≤0.025 to 5.5μg/mL.
The incidence of transient bacteremia using CDTR was the next lowest after amoxicillin (23.3%) among other oral antimicrobial agents with similar examination.

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Actinomycosis is a chronic suppurative and granulomatous disease caused primarily by Actinomyces israelii.
Recently, due to the widespread use of antibiotics, the incidence of actinomycosis is decreasing and demonstration of sulfur granules is becoming difficult. This situation makes diagnosis of actinomycosis difficult.
In this report, we present a case of actinomycosis which was suspected as a malignant tumor from the clinical and radiogical findings but which was later histopathologically diagnosed as actinomycosis.

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Levofloxacin (LVFX) concentrations in human serum, gingiva, mandibular bone, and dental follicle following a single oral administration of LVFX (200mg) were studied. The mean concentrations in serum, gingiva, mandibular bone, and dental follicle peaked at identical times, 1.5 h after administration, and were 2.29 μg/mL, 2.70, 1.33, and 2.46 μg/g, respectively. The mean concentration ratios of gingiva/serum, mandibular bone/serum, and dental follicle/serum at the peak time were 1.17, 0.60, and 1.13, respectively. Seventy percent of the LVFX concentrations in gingiva and dental follicle exceeded the MIC for 90% of clinically isolated strains of oral streptococci, but most of the LVFX concentrations in mandibular bone (4/5) did not exceed the MIC for 90% of clinically isolated strains of oral streptococci. The present results were obtained after a single dose study, however, higher concentrations of LVFX in oral tissues would be obtained after a multiple dose schedule.

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The importance of the cooperative function of osteopontin (OPN) and CD44 in cell adhesion, cell migration, immune responses and metastatic capacity of tumor cells has been confirmed recently. Our previous studies have shown that OPN colocalizes with CD44 inside embryonic fibroblasts, concanavalin A-activated human macrophages, and metastatic breast adenocarcinoma cell lines and plays a critical role in the migration of these cells. Also, we have reported that monolayer cultures of pre-fusion osteoclasts extend many pseudopods and fuse into large multinuclear osteoclasts, while these processes were suppressed in osteoclasts from the OPN-/- and CD44-/- mice. To further investigate the importance of OPN and CD44 in cell migration, especially in relation to cytoskeleton organization, we first analyzed the spatial relationship between OPN, CD44 and actin in pre-fusion osteoclasts generated from rat bone marrow monocytes. Immunofluorescence analyses showed that OPN colocalized with CD44 in the cell processes of osteoclast precursor cells. However, this colocalization was completely lost in the mature osteoclasts with actin ring. Next, we examined whether OPN influences the hyaluronan (HA) binding to CD44 in embryonic fibroblasts, using bead binding assay. In this study, the number of HA-coated beads attached to OPN-/- cells significantly reduced in comparison to OPN+/+ cells, whereas there was no difference in BSA- or fibronectin (FN) -coated bead attachment between OPN-/- and OPN+/+ cells, indicating that OPN influences the CD44 ligation by HA, but not FN. In conclusion, our present study using double-immunostaining analyses showes that OPN colocalizes with CD44 and actin in the cell processes in pre-fusion osteoclasts, while this colocalization was completely lost in the mature osteoclasts, both generated from rat bone marrow monocytes in the presence of M-CSF and RANKL. Moreover, bead binding assay indicates that OPN is critical for the CD44 binding to HA in embryonic mouse fibroblasts.

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The present study examined the effect of histatins on the growth of human gingival fibroblasts, the major constituents of gingival tissues. Histatins were isolated from fresh human parotid saliva by hydroxyapatite chromatography. Human gingival fibroblasts were prepared from explants of normal human tissues collected after obtaining informed consent. Human gingival fibroblasts were cultured with or without histatins. Cell growth was determined by the MTT assay. DNA synthesis was determined by the BrdU method. Ki-67 protein was detected by Western blot analysis. Binding of histatins to gingival fibroblasts was assayed using an optical biosensor. Histatins increased the rate of cell growth, DNA synthesis and the level of Ki-67 protein in human gingival fibroblasts. We also observed that histatins bound to human gingival fibroblasts. These results suggest that histatins promote the growth of human gingival fibroblasts. In the future, it may be possible to apply histatins to promote regeneration of human gingival fibroblasts in patients with periodontal disease.

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The ability of 17 β-estradiol (E₂) and its nine metabolites to induce apoptosis in Syrian hamster embryo (SHE) cells was investigated. When SHE cells were treated with E₂, estron (E₁), 2-hydroxyestrone (2-OHE₁), 4-hydroxyestrone (4-OHE₁), 2-metho-xyestrone (2-MeOE ₁), 16 α -hydoroxyestrone (16 α-OHE₁), 2-hydroxyestradiol (2-OHE₂), 4-hydroxyestradiol (4-OHE₂), 2-methoxyestradiol (2-MeOE₂) or estriol (E₃) at 0.1-10 μ g/mL for 48 h, the abilities of these estrogens to induce apoptosis were ranked as follows: 2-MeOE₂>2-OHE₁≅2-OHE₂>4-OHE₁≅4-OHE₂>2-MeOE₁>E₂>>E₁, 16α-OHE1≅E₃. These results corresponded to the cytotoxicities of these estrogens in SHE cells. Induction of apoptosis by E₂ Was not blocked by co-treatment with a pure antiestrogen ICI 182, 780, suggesting that estrogen-induced apoptosis in SHE cells is not medicated by estrogen receptors. Expression of p53 and p21 proteins was enhanced in SHE cells treated with the estrogens that induced apoptosis. In addition, cleavage of Bax protein was observed in SHE cells treated with these estrogens. These results indicate the differential abilities of E1, E2, and their metabolites to induce apoptosis in SHE cells which is medicated through p53 and Bax pathways.

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The cross infection risks in dental practice are well recognized, however, the current state of infection control procedures among dental care facilities is unclear. This study investigated the actual situation of infection control and occupational exposures in dental care facilities. A questionnaire survey was conducted among 1563 dentistry and oral surgery clinics in general hospitals and university hospitals. A total of 721 replies were received (46.1%) . Most facilities have an infection control committee, although a small number of dentists participate in that committee. Approximately 50% of the facilities carried out screening tests for hepatitis C virus in hospitalized patients. Occupational exposures occurred in 35.5% of the facilities. These accidents were mainly caused during the treatment of patients and operational clean-up procedures by needle for local anaesthesia. To reduce the incidence of these exposures, more training of dental staff may be required.

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