The majority of inflammatory diseases in the oral cavity arise from infections caused by several oral microorganisms inhabiting the biofilms formed on the surfaces of teeth, prosthetic devices, and oral mucosa. Human whole saliva is a mixture of secreted saliva from major and minor salivary glands. In addition, it also contains components derived from crevicular fluid. A number of families of peptides, such as cystatins, histatins, statherins, lipocalins (VEG protein), chromogranins, calprotectins and defensins, are found in whole saliva. In recent years, much attention has been focused on these peptides because they show antimicrobial activity against oral pathogens. These naturally occurring antimicrobial peptides are anticipated to be potent therapeutic agents for oral infectious diseases because the acquision of microbial resitance to antibiotics is one of the most serious problems for antibiotic therapy. The present paper reviews recent findings of studies on antimicrobial peptides found in saliva and salivary glands, with special reference to their nature and function in maintaining oral health. We further discuss the methodology in basic research on antimicrobial peptides as well as the possibility of their clinical use in oral health care science.

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p27 is a cyclin-dependent kinase (Cdk) inhibitor and plays an important role in negative regulation of the cell cycle during G0 and G1 phases. Protein level of p27 is controlled by ubiquitin-mediated proteolysis in cell cycle dependent manner. Therefore, degradation of p27 is a critical event for the G1/S transition and occurs through ubiquitination by SCF^Skp2 and subsequent degradation by the 26S proteasome. In various types of cancer including oral cancer, down-regulation of p27 is frequently observed. Importantly, down-regulation of p27 is well associated with its malignancy in various cancers. Moreover, It has been revealed that down-regulation of p27 in cancers is due to an enhancement of its degradation. More recent evidence suggests that Skp2 and Cks1, the specific recognition factors for p27 ubiquitination, are involved in down-regulation of p27 in cancer and have oncogenic properties. In the present review, we draw attention to p27 degradation in oral cancer.

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We investigated collagen formation during healing in an experimentally-created periosteal defect site (PDS) in terms of the immunohistochemical detection of Heat Shock Protein 47 (HSP47) and α -Smooth Muscle Actin ( α -SMA) along with the histopathological observation. In addition, we investigated expression of angiogenic factors, Vascular Endothelial Growth Factor (VEGF) and von Willebrand Factor (vWF), from the viewpoint of nutritional compensation for the bone in the PDS.
The histological findings showed that the PDS was filled with fibrin-like structure until 3 days postoperatively, with granulation tissue at 5 days postoperatively, and it was finally replaced by collagenous fibers. The reparative periosteum-like tissue at 84 days postoperatively, showed features similar to those of normal periosteum.
HSP47 and α -SMA showed a positive reaction in fibroblast-like cells as well as immature collagen fibers in the healing process of the PDS. At 84 days after operation, some of the fibroblast-like cells in the reparative periosteum-like tissue showed a positive reaction to HSP47 and α -SMA, similar to normal periosteum.
Some collagen fibers in the normal periosteum showed a positive reaction for vWF. Fibrin-like structure, granulation tissue including fibrobast-like cells and some collagen fibers in the PDS were positive for VEGF and vWF during the experimental term.
In conclusion, it is suggested that periosteal defects heal with regeneration of the collagenous structure, which has a role of nourishing the corresponding bone tissue.

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A case of ameloblastoma in a 67-year-old male Malay patient was reported with examination of Notch signaling. After histopathological observations and diagnosis, the distribution of transcription factors and mRNA of Notch1 and Jagged1 were examined by immunohistochemical (IHC) and in situ hybridization (ISH) techniques. Histopathologically, the tumor consisted predominantly of proliferating follicular nests of ameloblastoma epithelium randomly disposed in the fibrous stromal tissue. Some of these odontogenic epithelial nests showed features of central cystic degeneration, squamous metaplasia, and keratinizing pearl formation. By IHC, Notch1 and Jagged1 positive products were observed in most of these proliferating nests of ameloblastomas. Both of these gene expressions were detected by ISH in the cytoplasms of these IHC positive cells. These preliminary findings suggest that these genes may play a role in cytological differentiation or acquisition of tissue-specific characteristics in neoplastic cells of ameloblastomas.

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