Fogorvosi szemle, 2005 (98. évfolyam, 1-6. szám)
2005-04-01 / 2. szám
72 FOGORVOSI SZEMLE ■ 98. évf. 2. sz. 2005. tál healing (BSP, OP, OC, ON, PDGF, Collagen I) and of RUNX 2, a specific transcription factor in osteoblastic differentiation, were studied by RT-PCR. Results: In human PDL fibroblasts, most of the markers showed clear expression after 12 days and weaker expression after 5 and 16 days. Stimulation with EMD increased expression of OPN specific mRNA after 12 days. OC expression was not noted in stimulated or control PDL cell cultures although RUNX 2 specific mRNA was evident after 5 days. PRGF stimulated cells did not respond different to the controls. MC3T3-E1 cells showed expression of all markers including OC without differences between test and control cultures. Conclusions: Human PDL cells were able to express mRNA of markers associated with periodontal healing. When stimulated with EMD, OPN specific mRNA expression was increased. Stimulations with endogenous growth factors did not alter the mRNA expression. Acknowledgement: Supported by COST Action B23 and DFG grant GRK 325/3. F. SPOUTIL, I. HORÁCEK* Department of Zoology, Univ. of S-Bohemia, Ceské Budëjovice, ‘Department of Zoology, Charles University, Praha, Czech Republic ENAMEL PATTERNS IN A TRIBOSPHENIC MOLARS The microstructure and spatial variation in enamel structure was investigated in several species of bats with aid of SEM screening by serial sectioning of adult teeth. Enamel thickness is largely diversified within a tooth, being quite a large at the shearing walls and reduced almost to none at the cusp walls not engaged in the direct occlusion and at bottom of fossa and fossids. The enamel formation begins with dense parallel rods of prismatic enamel which later enlarge their diameters. Such a type of enamel formation and maturation is completed in unicuspid teeth but in molars it is retained only at the zone close to EDJ. Near to the enamel surface, the enamel maturation takes rather a form of infilling the space between rods of primordial prismatic enamel with finecrystal interprismatic matrix. The surface layer is then formed by very fine crystals of aprismatic enamel that shows a gradual transition to acellular cementum at basal slopes of cingular shelfs. It may take even more than a half of total enamel thickness at some parts of molars (fossa, lateral loops of cingula). The enamel formation begins in the way apomorphic to mammals (dense primatic enamel) while latter it is gradually replaced by a plesiomorphic way producing an increased amount of aprismatic enamel (IPM). The enamel formation typical for non-mammalian amniotes (dense aprismatic enamel of very fine crystals deposited parallel to EDJ, supposedlyquite a rapid) seems to be the major mechanisms by which the enamel maturation of a tribosphenic molar terminates. The adaptive and phylogenetic meaning of such arrangement is discussed. Acknowledgement: The study was supported by COST B23. M. HYTTINEN University of Kuopio, Department of Anatomy, Kuopio, Kuopio, Finland WHAT DIGITAL IMAGING CAN GIVE FOR EXTRACELLULAR MATRIX RESEARCH? Digital imaging techniques in microscopy offer powerful means for spatial localization and measuring of extracellular and intracellular matrix constituents. Rapid development of sensitive Peltier-cooled CCD detectors and desktop computing have enabled high-resolution visualization of tissue structure in two or three dimensions. Densitometrie techniques allow accurate and objective quantification of reporter molecule content or immunostaining intensity. The results can be interpreted using standardized absorbance/transmittance units. Accordingly, the method can be used for fluorescent proteins, metabolic tracers, or fluorochromes in different tissue or cell compartments. Measurements can be made from histological sections, cell cultures, gels, dot-blots, or microarrays. Modern computer-assisted polarized light microscopy can be used for visualization and quantification of the submicroscopic properties of collagen network in articular cartilage, in developing bone, or in demineralized bone. With the aid of Stoke s calculus is possible to create images which describe pixel-by-pixel (a) orientation-independent birefringence of polarized light by collagen, (b) degree of the mean parallelism of collagen fibrils, and (c) the mean angular orientation of collagen network. Recently, development of FTIRis (=”Fourier- Transform Infra Red imaging spectroscopy”) has made possible direct imaging of several organic and inorganic macromolecules simultaneously from cryosections or fixed tissue sections embedded either in paraffin or methyl-metachrylate. In bone (tooth) and cartilage analysis, co-localization of collagens, proteoglycans, dentin, or hydroxyapatite is possible. The advantage is that all the measurements can be made form the same specimen non-destructively. Measurements can be made with 6-10pm spatial resolution. Acknowledgement: The support of COSTB23 program is gratefully acknowledged.
