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Probiotics or health-beneficial bacteria have only recently been introduced in dentistry and oral medicine after years of successful use in mainly gastro-intestinal disorders. The concept of bacteriotherapy and use of health-beneficial micro-organisms to heal diseases or support immune function was first introduced in the beginning of the 20th century. Later the concept lead to the development of modern dairy industry and even today most probiotic strains are lactobacilli or bifidobacteria used in milk fermentation. The mechanisms of probiotic action are mainly unknown but the intermicrobial species interactions are supposed to play a key role in this together with their immuno-stimulatory effects. The introduction of probiotic bacteria in the mouth calls for ascertainment of their particular safety. Since acid production from sugar is detrimental to teeth, care must be taken not to select strains with high fermentation capacity. The first randomized controlled trials have nevertheless shown that probiotics may control dental caries in children due to their inhibitory action against cariogenic streptococci. Less evidence exists on their role in periodontal disease or oral yeast infections. Furthermore the best vehicles for oral probiotic applications need to be assessed. So far mainly dairy products have been investigated but other means such as probiotics in chewing gums or lozenges have also been studied. From the clinical practitioner’s point of view direct recommendations for the use of probiotics cannot yet be given. However, scientific evidence so far indicates that probiotic therapy may be a reality also in dentistry and oral medicine in the future. IN VITRO EVALUATION OF YOGHURT STARTER LACTOBACILLI AND LACTOBACILLUS RHAMNOSUS GG ADHESION TO SALIVA-COATED SURFACES. STAMATOVA I, KARI KIRSTI, VLADIMIROV S, MEURMAN JUKKA H. Oral microbiology and immunology. 24(3): 218-223, 2009. AIM: The aim of the study was to evaluate the adhesion of Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus rhamnosus strain GG to saliva-coated surfaces in vitro. METHODS: Fifteen radiolabeled dairy L. delbrueckii subsp. bulgaricus strains and L. rhamnosus GG were tested for their ability to adhere to saliva-coated hydroxyapatite beads and polystyrene microtiter plates and the radioactivity was measured by liquid scintillation counter. The effects of lysozyme on the adhesion of lactobacilli and of pretreatment with lactobacilli on the adhesion of Streptococcus sanguinis were also assessed. RESULTS: All strains tested adhered to saliva-coated surfaces but with significantly different binding frequencies. The adhesion of the L. delbrueckii subsp. bulgaricus strains remained lower in comparison to L. rhamnosus strain GG. One L. delbrueckii subsp. bulgaricus strain showed binding frequency comparable to S. 71 sanguinis. Lysozyme pretreatment of the samples significantly increased lactobacillus adhesion to saliva-coated surfaces. CONCLUSION: The present results showed signifycant variations in the adhesion capacity of the Lactobacillus strains studied. Adhesion to oral surfaces is of primary importance for bacterial colonization in the mouth. Only one of the L. delbrueckii subsp. bulgaricus dairy starter culture strains investigated had a high adhesion percentage. This strain might then be considered for further investigations in the oral environment. A NOVEL AND SELECTIVE MEMBRANE TYPE-1 MATRIX METALLOPROTEINASE (MT1-MMP) INHIBITOR REDUCES CANCER CELL MOTILITY AND TUMOR GROWTH. SUOJANEN JUHO, SALO TUULA, KOIVUNEN ERKKI, SORSA TIMO, PIRILÄ EMMA. Cancer biology & therapy. 8 (24): 2362-2370, 2009 Matrix metalloproteinases (MMPs), and especially membrane type-1 matrix metalloproteinase (MT1-MMP, MMP-14), play a role in cancer progression and can have a prognostic value. Various synthetic broad-spectrum MMP inhibitors have been developed but have had little success in cancer patient treatment owing to side effects. Until recently, selective targeting of specific MMPs has not been possible due to lack of specific inhibitors. Here we have developed a selective MT1-MMP peptide-inhibitor GACFSIAHECGA, which did not affect the activities of many other MMPs including MMP-1, -2, -3, -7, -8, -9, -10, -11, -12, -13, -15, -17 or -20. In a fluorescent peptide cleavage assay it displayed an IC(50) value of 150 microM. The peptide effectively inhibited the migration and invasion of cancer cell lines in vitro. Furthermore, in vivo the peptide reduced the growth of tongue carcinoma xenografts and prolonged the survival of mice. Overall these results suggest that selective MT1-MMP inhibitors may have utility as anticancer agents. TRANEXAMIC ACID CAN INHIBIT TONGUE SQUAMOUS CELL CARCINOMA INVASION IN VITRO. SUOJANEN JUHO, SORSA TIMO, SALO TUULA Oral diseases. 15 (2): 170-175, 2009. OBJECTIVES: Tranexamic acid (TA) is an inhibitor of plasminogen activation commonly used in surgery. Plasmin, the end product of plasminogen activation, degrades fibrin in the thrombus, leading to thrombolysis. However, plasmin is also associated with progression of several cancers and with cancer-associated matrix metalloproteinase-9 (MMP-9) activation. As the gelatinases MMP-2 and -9 are involved in cancer progression, several antigelatinolytic drugs have been developed as potential anticancer