Immunolocalization of Runx2 and Osterix in the Developing Periodontal Tissues of the Mouse

Runx2 and Osterix, the transcription factors for osteoblast differentiation, are known as fundamental factors to regulate the development of calcified tissues. However, the biological functions of these factors in the development of the periodontal tissues remain unclear. In this study, we investigated the distribution of Runx2 and Osterix during periodontal tissue development of the mice. Mandibles from 14-day-old mice were prepared for paraffin section. Serial sections of the mandible containing 1st molar tooth germs were obtained as a thickness of 7 microm. Some sections were stained with hematoxylin and eosin. Others were used for immunohistochemistry for PCNA, Runx2, and Osterix. Epithelial cells in growing end of Hertwig's epithelial root sheath (HERS) and mesenchymal cells adjacent to the growing end of HERS expressed PCNA. Undifferentiated mesenchymal cells and hard tissue forming cells like cementoblasts and osteoblasts in early stage of differentiation expressed Runx2. Fully differentiated cementoblasts and osteoblasts secreting matrix proteins expressed Osterix. However, the cells terminated the matrix formation did not express Osterix. Periodontal ligament cells expressed Runx2 and Osterix. Pulp cells expressed Runx2 only.These results suggest that Runx2 and Osterix might regulate the differentiation of cementoblasts in the same manner as osteoblasts. Runx2 might participate in the process of cementoblast differentiation in early stage, whether Osterix might regulate the maturation and matrix synthesis of the cells.

Fourier Analysis of Maxillary Dental Arch Forms / 체질인류학회지

Our previous principal component analysis conducting on reference points, lines and angles, and a vectordeveloped polar coordinate system has elucidated that the components of eigenvectors had positive relationships in the curvature of anterior teeth segment, between the protrusion of canines and degree of arch roundness, and in the length-to-width ratio of 62 maxillary dentitions, which were preliminarily classified with reference to the conventional Thompson's morphological descriptions for dental arch forms. In the present study on morphological characters of the maxillary dentitions, we conducted a Fourier analysis on the previously obtained data. We observed that the amplitude of 2nd, 3rd and 4th Fourier harmonics were closely correlated with the length-to-width ratio, curvature of the anterior teeth segment, and the curvilinear contour of maxillary dental arches. In addition, the relationships between previously estimated data and the constant value and the amplitude of the Fourier series were examined by analysis of correlation coefficients (p<0.01). The results of the present study suggest that the morphology of maxillary dentitions consists of three essentials-the length-to-width ratio, the curvature of anterior teeth and the curvilinear contour of dental arches.

Anti-candidal Effect of Polyphosphate

Candida albicans is a commensal yeast normally present in small numbers as normal oral flora. In a certain condition, however, the yeast may proliferate and/or become invasive resulting in oral candidiasis such as denture stomatitis, and may even cause life-threatening systemic candidiasis. The present study was undertaken to test whether polyphosphate (polyP), which has been shown to be a strong antibacterial agent against a variety of oral pathogens, has antifungal effect on C. albicans. C. albicans ATCC 90027 was grown in Sabouraud-Dextrose broth with or without polyP. Anti-C. albicans activity of polyPs with various chain lengths was determined by measuring the growth of candidal cells at 540 nm. polyPs with chain length of 3 (polyP3) or higher effectively inhibited the candidal growth when added at the very beginning of the culture, whereas orthophosphate and pyrophosphate failed to do so. At the concentration of 0.05 percent, all the polyPs tested inhibited candidal growth. The effect of polyP65 that showed stronger anti-candidal effect than others at the concentrations tested and of Calgon (hexametapolyphosphate, practical grade) was further examined. The concentration of 0.03 percent was enough for polyP65 and Calgon to suppress candidal growth throughout the 48-h incubation. PolyP65 added to the growing C. albicans at its exponential phase was as much effective in inhibiting the candidal growth as added at the very beginning of the culture. It was found that 93.8 and 96.9 percent of the yeast cells lost their viability when polyP65 was added to growing C. albicans at the concentrations of 0.03 and 0.05 percent, respectively. Intracellular nucleotide release from the candidal cells incubated with polyP65 was only slightly increased and the nucleotide release was not reversed by the addition of divalent metal ions like Mg++ and Ca++. Under the transmission electron microscope, although the majority of growing C. albicans cells appeared to be atypical in their shape in the presence of polyP65, only a small number of the cells were observed to be lysed. The overall results suggest that polyP has a strong fungicidal activity against C. albicans, in which chelation-mediated cell lysis may not play the major role, but other novel mechanisms that possibly affect the viability of the yeast may be involved. Since polyP also has a strong antibacterial effect on oral pathogens, it may well be used for the prevention and treatment of a variety of oral diseases caused by a wide spectrum of microorganisms including C. albicans.

Measurement of Central Keratometric Value with Orbscan II(R) Topography after LASIK

PURPOSE: To compare central keratometric values (K-values) measured at the pupillary center by Orbscan II (R) topography (Orbtek, Bausch & Lomb, USA) with preexisting methods for K-values in patients who have been treated with laser in situ keratomileusis (LASIK). METHODS: A total of 36 consecutive eyes of 25 patients who were treated with LASIK for myopia have been followed up for more than 1 year. Central K-values measured by Orbscan II(R) topography, K-values measured with autorefractokeratometer, and refraction-derived K-values were compared . RESULTS: The mean central keratometric K-value measured by Orbscan II (R) topography was 39.65+/-1.94 (35.82 to 43.45) diopter (D), and was not statistically significantly different from the mean refraction derived K-value which was 39.63+/-1.95 D (35.95 to 43.41) (p>0.05), but was statistically lower than the mean K-value measured with autorefractokeratometer which was 40.23+/-1.76 D (36.56 to 43.69) (P<0.05). CONCLUSIONS: In patients who have been treated with LASIK for myopia, central keratometric K-value measured with Orbscan II R topography is not statistically significantly different from refraction derived K-value, but is lower than K-value measured with autorefractokeratometer.

Effect Of Polyphosphate On Skin Wound Healing

Peripheral Corneal Ulcer after Simultaneous Surgery for Cataract and Pterygium: Secondary Mooren's Ulcer

PURPOSE: To report a previously unreported secondary Mooren's ulcer associated with simultaneous sur-gery for cataract and pterygium. METHODS: Case report. Five days after simultaneous surgery for cataract and pterygium, an 86-year-old woman developed severe pain and a superior and inferior peripheral corneal ulcer that had the characteristic clinical appearance of Mooren's ulcer. RESULTS: Peripheral corneal ulcer is rapidly progressive, painful, beginning at the limbus with a gray, overhanging, infiltrated edge at its central border. She had no history of collagen-vascular disease, negative serologic test result, and negative culture for pathogen. Surgical trauma may have been the inciting factor in development of the ulcer. She was treated with topical and systemic steroids. After complete control of the inflammation, the patient remained in remission.

Effect of Inorganic Polyphosphate on Cultured Periodontal Ligament Cells / 체질인류학회지

This study was designed to examine the effect of polyP on the periodontal ligament fibroblasts. The cells were incubated for 24 and 48 hours with various concentrations (0.001%, 0.002%, 0.005%, 0.010%, 0.020%, 0.040%) of polyP. Cell activity, alkaline phosphatase activity, and protein synthesis activity of the cells were examined. The results were as follows: 1. Twenty four hours after incubation with polyP, the cell activity of the periodontal ligament fibroblasts was increased. Forty eight hours after polyP application, the activity of the cells was similar to that of control group. 2. Twenty four or forty eight hours after incubation with polyP, the alkaline phosphatase activity of the periodontal ligament fibroblasts was increased. 3. The protein synthesis of the periodontal ligament fibroblasts was not changed after polyP application. These results suggest that, polyP may increase the cell activity and alkaline phosphatase activity of periodotal ligament fibroblasts and polyP may not affect the protein synthesis of the cells.

Possibility of involvement of Porphyromonas gingivalis in coronary heart disease

Porphyromonas gingivalis has been implicated in periodontal diseases. Accumulating evidence suggests that cardiovascular disease is the most prevalent medical problem in patients with periodontal diseases. In order to check the possibility that P. gingivalis is involved in coronary heart disease, the present study was performed to observe P. gingivalis adherence and invasion of human coronary artery endothelial cells (HCAEC) and production of cytokines and growth factors by HCAEC upon P. gingivalis infection. 3H-labeled P. gingivalis 381 was incubated with HCAEC for 90 min. The radioactivity of the washed HCAEC was a measure of the absorbed (adhering and invading) P. gingivalis. The absorption radioactivity of the HCAEC infected by P. gingivalis was determined to be 59.58% of the input bacterial cells. In contrast, the absorption radioactivity of the cells infected by S. gordonii Challis which was employed as a control was negligible (0.59%). DPG3, a P. gingivalis mutant defective of fimbriae, appeared to be impaired to some extent in capability of adherence/invasion as compared to that of the parental strain 381, showing 43.04% of the absorption radioactivity. The absorption radioactivity of the HCAEC infected by P. gingivalis 381 in the presence of excessive fimbriae at the concentrations of 50 mug and 100 mug/ml was 57.27 and 45.44%, respectively. Invasion of HCAEC by P. gingivalis 381 was observed by an antibiotic (metronidazole) protection assay and transmission electron microscopy (TEM). In the antibiotic protection assay, invasion by the bacterium was measured to be 0.73, 1.09, and 1.51% of the input bacterial cells after incubation for 30, 60, and 90 min, respectively. Invasion by DPG3 was shown to be 0.16% after 90-min incubation. In comparison of invasion efficiency at 90 min of the incubation, the invasion efficiency of DPG3 was 0.37% while that of its parental strain 381 was 2.54%. The immunoblot analysis revealed fimbriae of P. gingivalis did not interact with the surface of HCAEC. These results suggest that fimbriae are not the major contribution to the adherence of P. gingivalis to HCAEC but may be important in the invasion of HCAEC by the bacterium. The presence of cytochalasin D (1 mug/ml) and staurosporine (1 muM) reduced the invasion of HCAEC by P. gingivalis 381 by 78.86 and 53.76%, respectively, indicating that cytoskeletal rearrangement and protein kinase of HCAEC are essential for the invasion. Infection of P. gingivalis induced HCAEC to increase the production of TNF-alpha by 60.6%. At 90 min of the incubation, the HCAEC infected with P. gingivalis cells was apparently atypical in the shape, showing loss of the nuclear membrane and subcellular organelles. The overall results suggest that P. gingivalis may cause coronary heart disease by adhering to and invading endothelial cells, and subsequently damaging the cells.

Antibacterial Effect of Polyphosphates on Porphyromonas gingivalis

Porphyromonas gingivalis is strongly implicated in the pathogenesis of adult periodontitis, the major cause of tooth loss in adults. Use of an antibacterial agent controlling P. gingivalis as a periodontal therapeutic agent has been rationalized. The present study was performed to observe the antibacterial effect of inorganic polyphosphates (polyP) on P. gingivalis. P. gingivalis 2561 was grown in half-strength brain-heart infusion broth containing hemin and vitamin K with or without polyP. Minimal inhibitory concentration (MIC) of polyP with various chain lengths was determined by measuring the absorbance of the grown cells at 540 nm. MIC of polyP for the bacterium was determined to be 0.05%. The effect of polyP with a chain length of 75 (polyP 75) was further examined. PolyP 75 added to the growing culture of P. gingivalis at its exponential phase was as effective in inhibiting the growth of P. gingivalis as polyP 75 added at the very beginning of the culture. More than 99% of the cells lost their viability determined by viable cell count when polyP 75 was added to the culture of growing P. gingivalis at the concentration of 0.06%, suggesting that polyP 75 has a bactericidal effect on the bacterium. Intracellular nucleotide release from the cells was increased by approx. 20% in the presence of polyP 75 but was not reversed by the addition of divalent cations like Ca++ and Mg++. Under the transmission electron microscope, only a small number of the growing P. gingivalis cells were actually lysed. However, the majority of the cells appeared to be atypical in their shape, demonstrating accumulation of highly electron-dense granules and bodies of condensed nucleic acid-like material in the cytoplasm. In the presence of polyP 75, the protein profile of P. gingivalis was changed as determined by SDS-polyacrylamide gel electrophoresis and immunoblot, and the proteolytic activity of the bacterium demostrated on the zymograms was decreased. The overall results suggest that polyP have a strong bactericidal activity against P. gingivalis in which lysis in relation to chelation may not play the major role but unknown mechanism that possibly affects the viability of the bacterium may be involved. PolyP may be used as an agent for prevention and treatment of periodontitis.