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Oral Tissues (oral + tissue)
Selected AbstractsProtection of the oral mucosa by salivary histatin-5 against Candida albicans in an ex vivo murine model of oral infectionFEMS YEAST RESEARCH, Issue 5 2010Brian M. Peters Abstract The oral cavity is a primary target for opportunistic infections, particularly oral candidiasis caused by Candida albicans. A commensal fungus commonly colonizing mucosal surfaces, under conditions of immune dysfunction, C. albicans can become a pathogen causing recurrent infections. Yet, the role of host oral innate immunity in the development of candidiasis is not fully elucidated. Specifically, the host salivary antimicrobial peptide histatin-5 (Hst-5) has been proposed to play a protective role in the oral cavity against C. albicans. However, investigations demonstrating its efficacy on oral tissue have been lacking. To this end, in this study, an ex vivo murine model of oral infection was developed. Viable C. albicans counts and histopathological analyses demonstrated a significant protective effect for Hst-5 on mouse oral tissue against C. albicans. More importantly, host saliva exerted a comparable anticandidal effect. However, this effect was neutralized upon treatment of saliva with proteases and C. albicans, previously shown to degrade Hst-5, indicating that Hst-5 is likely the salivary component responsible for the observed protection. Combined, the findings from this study demonstrate for the first time the efficacy of salivary Hst-5 in protecting host oral tissue against C. albicans infection, thereby affirming the therapeutic potential of this natural host peptide. [source] Vision enhancement system for detection of oral cavity neoplasia based on autofluorescenceHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 3 2004Ekaterina Svistun MS Abstract Background. Early detection of squamous cell carcinoma (SCC) in the oral cavity can improve survival. It is often difficult to distinguish neoplastic and benign lesions with standard white light illumination. We evaluated whether a technique that capitalizes on an alternative source of contrast, tissue autofluorescence, improves visual examination. Methods. Autofluorescence of freshly resected oral tissue was observed visually and photographed at specific excitation/emission wavelength combinations optimized for response of the human visual system and tissue fluorescence properties. Perceived tumor margins were indicated for each wavelength combination. Punch biopsies were obtained from several sites from each specimen. Sensitivity and specificity were evaluated by correlating histopathologic diagnosis with visual impression. Results. Best results were achieved with illumination at 400 nm and observation at 530 nm. Here, sensitivity and specificity were 91% and 86% in discrimination of normal tissue from neoplasia. This compares favorably with white light examination, in which sensitivity and specificity were 75% and 43%. Conclusions. Oral cavity autofluorescence can be easily viewed by the human eye in real time. Visual examination of autofluorescence enhances perceived contrast between normal and neoplastic oral mucosa in fresh tissue resections. © 2004 Wiley Periodicals, Inc. Head Neck26: 205,215, 2004 [source] RNA from brush oral cytology to measure squamous cell carcinoma gene expressionJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 2 2008Joel L. Schwartz Background:, RNA expression analysis of oral keratinocytes can be used to detect early stages of disease such as oral cancer or to monitor on-going treatment responses of the same or other oral diseases. A limitation is the inability to obtain high quality RNA from oral tissue without using biopsies. While oral cytology cell samples can be obtained from patients in a minimally invasive manner they have not been validated for quantitative analysis of RNA expression. Methods:, As a starting point in the analysis of tumor markers in oral squamous cell carcinoma (OSCC), we examined RNA in brush cytology samples from hamsters treated with dibenzo[a,l]pyrene to induce oral carcinoma. Three separate samples from each animal were assessed for expression of candidate marker genes and control genes measured with real-time RT-PCR. Results:, Brush oral cytology samples from normal mucosa were shown to consist almost exclusively of epithelial cells. Remarkably, ß-2 microglobulin and cytochrome p450, 1B1 (CYP1B1) RNA showed potential utility as markers of OSCC in samples obtained in this rapid and non-surgical manner. Conclusion:, Brush oral cytology may prove useful as a source of RNA for gene expression analysis during the progression of diseases of the oral epithelium such as OSCC. [source] Loss of heterozygosity at APC and MCC genes of oral cancer and leukoplakia tissues from Indian tobacco chewersJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 8 2003Nilabja Sikdar Abstract Background:, Loss of heterozygosity (LOH) at tumor suppressor genes, such as adenomatous polyposis coli (APC) and mutated in colon cancer (MCC) genes, is one of the early events in carcinogenesis of oral tissue in Caucasian and Chinese patients. We wanted to check whether it is also true in Indian oral pre-cancer and cancer patients. Methods:, Loss of heterozygosity at APC and MCC genes was investigated in 57 and 40 unrelated primary oral leukoplakia (a pre-cancerous lesion) and squamous cell carcinomas (SCC), respectively, by polymerase chain reaction. Results:, In these samples, most of the leukoplakia patients had tobacco smoking habit whereas majority of cancer patients had tobacco chewing habit. LOH at APC gene was observed in 4 of 16 (25%) and 1 of 29 (3%) informative tumor and leukoplakia DNAs from tobacco chewers, respectively. LOH at MCC gene was not detected either in tumor or in leukoplakia DNAs. Conclusion:, This infrequent LOH at APC gene of pre-cancer and cancer tissues suggests that it may not be an early event in oral carcinogenesis in these patients. [source] Immunohistochemical analysis of Th1/Th2 cytokine profiles and androgen receptor expression in the pathogenesis of nifedipine-induced gingival overgrowthJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2003W-T. Huang Background:, Numerous studies have demonstrated that gingival overgrowth may be associated with androgen and cytokine expression in tissues. Objectives:, The aim of this study was to compare the expression of androgen receptor-presenting cells (AR+ cells) and Th1/Th2 cytokine [Th1: interleukin (IL)-2, interferon-, (IFN-,); Th2: IL-4, IL-10, IL-13] expression cells in tissue sections of patients with gingival overgrowth. Materials and methods:, Tissue samples were collected from patients with healthy periodontium (H group), adult periodontitis (P group), surgically extracted teeth (S group), and nifedipine-induced gingival overgrowth (NIGO group). The clinical periodontal parameters of pocket depth (PD), bleeding on probing (BOP), and plaque control record (PCR) were measured around selected sample teeth. Gingival biopsies were further processed by immunohistochemical staining method. The expressions of cells positive for AR, IL-2, IFN-,, IL-4, IL-10, and IL-13 were counted by predetermined semiquantitative methods. Results:, Our results indicated that AR, IL-2, IFN-,, IL-4, IL-10, and IL-13 were intensively expressed in the nuclei of inflammatory cells and fibroblasts of gingival connective tissue. Stronger expressions of AR, IL-2, and IFN-, were found in the NIGO group. The AR+ cells/0.01 mm2 in gingival fibroblasts were significantly higher in the NIGO group (80.2 ± 10.7) than those of the periodontitis group (52.5 ± 11.8) and control group (37.4 ± 11.3) (P < 0.05). The cytokine expression of the NIGO group showed a trend towards Th1-type expression (IL-2; P = 0.0001). In the surgically extracted tooth group, a stronger expression of Th2-type cytokine (IL-4, Il-10, IL-13; P < 0.05) was found in inflammatory cells. In a comparison of the IL-2/IL-4-labeled cell ratio of the four groups, a descending sequence was discovered as NIGO group (0.92 ± 0.97) > H group (0.81 ± 0.61) > P group (0.77 ± 0.82) > S group (0.58 ± 1.77). Conclusions:, Our data support the following: (i) taking nifedipine may elevate the expression of AR in susceptible oral tissue, e.g. gingiva; (ii) the cytokine profile of T-cells in NIGO tissue indicates a trend preferentially towards Th1 activity; and (iii) elevation of AR expression cells and prominent Th1 cytokine-labeled cells are two significant factors in the pathogenesis of NIGO. [source] Spectroscopic detection and evaluation of morphologic and biochemical changes in early human oral carcinoma,CANCER, Issue 7 2003Markus G. Müller Ph.D. Abstract BACKGROUND Understanding the development and progression of head and neck squamous cell carcinoma is key in the quest for the early diagnosis and prevention of this type of malignancy. The current study correlated early biochemical and histologic changes in oral tissue with spectral features in fluorescence, reflectance, and light scattering spectra acquired in vivo to diagnose early stages of oral malignancies. METHODS A total of 91 tissue sites from 15 patients with varying degrees of malignancy (normal, dysplastic, and cancerous sites) and 8 healthy volunteers were analyzed with 3 spectroscopic techniques. Direct biochemical information regarding oral tissue native fluorophores was obtained with intrinsic fluorescence spectroscopy by fitting a linear combination of collagen and the reduced form of nicotinamide adenine dinucleotide (NADH) fluorescence spectra to the intrinsic tissue fluorescence spectra excited with 337 nanometer (nm) and 358-nm laser light. Diffuse reflectance spectroscopy was used to provide information regarding tissue absorption and structure, such as hemoglobin concentration and stroma density, by measuring the wavelength-dependent absorption and scattering coefficients. By subtracting the diffusely reflected component from the measured reflectance, light scattering spectroscopy (LSS) information resulting from single backscattering from epithelial cell nuclei was obtained. LSS provides information concerning the size distribution of cell nuclei. RESULTS These optically extracted tissue parameters provide biochemical or structural information in vivo without the need for tissue excision, and can be used to diagnose tissue abnormalities. By combining the information provided by the three techniques, a method known as trimodal spectroscopy, a sensitivity and specificity of 96% and 96%, respectively, in distinguishing cancerous/dysplastic (mild, moderate, and severe) from normal tissue was achieved. In addition, the authors were able to distinguish dysplastic from cancerous tissue with a sensitivity of 64% and a specificity of 90%. CONCLUSIONS The results of the current study demonstrated that Trimodal spectroscopy is a highly sensitive and specific technique with which to diagnose tissue abnormalities. Cancer 2003;97:1681,92. © 2003 American Cancer Society. DOI 10.1002/cncr.11255 [source] Inflammatory nerve responses in the dental pulpENDODONTIC TOPICS, Issue 1 2007INGE FRISTAD Tooth pulp has a dense innervation and a rich vascular supply to maintain homeostasis and to preserve the integrity of the tissue. Function, trauma, and antigenic challenges make teeth and supporting tissues susceptible to tissue injury and inflammation, partially due to the lack of collateral blood and nerve supply and to their low compliance. This review focuses on dental nerve functions and adaptive changes in the pulpal nerve supply following inflammation and peripheral injury. Overviews of dental innervation and its development and of the peptidergic innervation of oral tissues are presented, followed by a discussion of peripheral and central changes after local insults to teeth and peripheral nerve injuries. The functional implications of these adaptive changes are considered. Received 13 February 2009; accepted 3 September 2009. [source] Oral biopsies from patients with orofacial granulomatosis with histology resembling Crohn's disease have a prominent Th1 environmentINFLAMMATORY BOWEL DISEASES, Issue 4 2007Jona Freysdottir BSc Abstract Background: Orofacial granulomatosis (OFG) is an idiopathic inflammatory disorder of children and young adults whose clinical symptoms include swelling of the lips or face, mucosal nodularity (cobblestoning), mucosal tags, hyperplasia of the gingivae, and aphthous oral ulcers. Whether some OFG patients with clinical and histological characteristics resembling Crohn's disease (CD) are a special group (oral CD) or true CD patients with symptoms reaching all the way to the oral mucosa remains to be determined. Methods: In this study oral biopsies from 10 patients with OFG were analyzed for the presence of T cells, T-cell subsets, B cells, and macrophages, as well as cytokines (IL-4, IL-10, IFN-,, IL-12, and TNF-,), chemokines (RANTES and MIP-1,), and chemokine receptors (CCR3, CCR5, and CXCR3). For comparison, oral tissues from 7 patients with other granulomatous diseases were included. Results: Compared with the non-OFG group, the OFG group had raised levels of CD4+ T cells, IFN-,, IL-10, and RANTES but reduced levels of CD68+ macrophages outside the granulomas, whereas within the granulomas the levels of CD3+ and CD4+ T cells and of IFN-, were raised, but the levels of IL-4 were decreased. These data are indicative of a Th1 environment within the oral OFG tissues, which resembles that already observed in gut CD tissues. Conclusions: Therefore, it can be concluded that some OFG patients have both histopathological and immunopathological features that resemble those observed in CD patients. (Inflamm Bowel Dis 2006) [source] Stromelysin-3 expression is an early event in human oral tumorigenesisINTERNATIONAL JOURNAL OF CANCER, Issue 2 2003Shilpi Soni Abstract Stromelysin-3 (ST3/MMP11) is associated with human tumour progression. To determine the clinical significance of ST3 in oral tumorigenesis, its expression was analysed in different stages of tobacco-associated oral cancer. Immunohistochemical analysis of ST3 expression in 79 oral precancerous lesions, 177 SCCs and 35 histologically normal oral tissues was carried out and corroborated by immunoblotting and RT-PCR. ST3/MMP11 protein expression was observed in 45/79 (57%) precancerous lesions [28/48 (58%) with hyperplasia and 17/31 (55%) with dysplasia] and in 123/177 (70%) oral SCCs. In precancerous lesions, ST3 expression was higher compared to normal oral tissues (p = 0.000) and associated with MVD (p = 0.05), a marker for angiogenesis. ST3 was also expressed in cells cultured from precancerous and cancerous lesions that had undergone epithelial-to-mesenchymal transition. In oral cancer patients, ST3 positivity was associated with lymph node involvement (p = 0.025) and increased intratumoral MVD (p = 0.009). Ninety-eight oral SCC patients were followed up for a period of 94 months (median 22.5 months). Kaplan-Meier survival analysis showed that ST3 expression was not a significant prognostic indicator. ST3 expression in oral hyperplastic and dysplastic lesions suggests its association with progression of phenotypic alterations acquired early during the malignant transformation pathway of oral epithelium and implicates it not only in angiogenesis and invasion but also in tumorigenesis. Thus, ST3 may serve as a potential target for developing molecular therapeutics for early intervention in oral tumorigenesis. © 2003 Wiley-Liss, Inc. [source] Amylase and cyclic amp receptor protein expression in human diabetic parotid glandsJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 9 2010Monica Piras J Oral Pathol Med (2010) 39: 715,721 Background:, Salivary dysfunction and oral disorders have been described in both type 1 and type 2 diabetes mellitus. However, the cellular and molecular consequences of diabetes on oral tissues remain to be ascertained. The purpose of this investigation was to study, by means of electron microscopy, the morphologic and molecular changes that occur in salivary glands during diabetes. Methods:, Biopsy samples of parotid glands were excised from non-diabetic and diabetic (type 1 and type 2) consenting patients and processed by standard methods for routine morphology and electron microscopic immunogold labeling. Specific antibodies were used to determine and quantify the expression of secretory proteins (alphaamylase and the regulatory subunit of type II protein kinase A). Results:, Morphologic changes in the diabetic samples included increased numbers of secretory granules, and alterations in internal granule structure. Quantitative analysis of immunogold labeling showed that labeling densities were variable among the parotid gland samples. In type 1 diabetes amylase expression was greater than in non-diabetic glands, whereas in type 2 diabetes it was not significantly changed. Expression of type II regulatory subunits was slightly, although not significantly, increased in acinar secretory granules of type 1 diabetic samples and was unchanged in type 2 diabetic samples. Conclusions:, Our data show that diabetes elicits specific changes in secretory protein expression in human salivary glands, thus contributing to the altered oral environment and oral disease associated with diabetes. [source] Vascular endothelial growth factor (VEGF) expression in oral tissues: possible relevance to angiogenesis, tumour progression and field cancerisationJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 8 2001J. Carlile Abstract: The aim of this study was to assess whether vascular endothelial growth factor (VEGF) expression in oral tissues is associated with angiogenesis, disease progression or field cancerisation. Vascularity and VEGF immunoreactivity were quantified in 68 archival specimens including normal oral mucosa (NOM), dysplasia (DYS) and squamous cell carcinoma (SCC). Vascularity increased significantly with disease progression; it was also higher in NOM adjacent to SCC than in NOM from healthy tissue, suggesting an association with field cancerisation. VEGF expression in epithelial cells was evaluated using two antibodies and three indices. VEGF indices and vascularity were not directly correlated. The expression of VEGF was similar in all DYS and NOM specimens, whether or not adjacent to a concurrent lesion. A comparison of SCC with NOM or DYS led to opposite results, depending on the VEGF antibody and index used. We conclude that VEGF expression in the oral mucosa may play a physiological role, but does not appear to be associated with angiogenesis, field cancerisation or transition to dysplasia. Further studies concerned with tumour development require examining specific VEGF isoforms and standardisation of the methodology. [source] Hydrogen sulfide inhibits cell proliferation and induces cell cycle arrest via an elevated p21Cip1 level in Ca9-22 cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2008H. Takeuchi Background and Objective:, Volatile sulfur compounds such as hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) are the main causes of oral malodor. However, the physiological functions of H2S have not been investigated in oral tissues. The aim of this study was to evaluate the effect of H2S on cell proliferation and the cell cycle in oral epithelial-like cells. Material and Methods:, Ca9-22 cells were used in this study. Cells were cultured in 5% CO2/95% air with (5 or 10 ng/mL) or without H2S. DNA synthesis was measured using a 5-bromo-2-deoxyuridine enzyme-linked immunosorbent assay. The cell cycle was analyzed using a flow cytometer. The expressions of phosphorylated retinoblastoma protein (Rb), p21Cip1 and p27Kip1 were evaluated by western blotting. Results:, Exposure to 5 and 10 ng/mL of H2S significantly decreased DNA synthesis (p < 0.05). Cell cycle analysis also showed that exposure to both concentrations of H2S significantly increased the proportion of cells in G1 phase (p < 0.001) and significantly decreased the proportion of cells in S phase (p < 0.01). Western blotting showed that Rb phosphorylation was reduced and p21Cip1 was enhanced by exposure to H2S. Conclusion:, The results indicated that H2S inhibits cell proliferation and induces cell cycle arrest via the expression of p21Cip1 in Ca9-22 cells. [source] Growth factors and proliferation of cultured rat gingival cells in response to cyclosporin AJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2005Takumasa Yoshida Objective:, The prominent side-effect of cyclosporin A, an immunosuppressive drug, in oral tissues is gingival outgrowth, although the exact mechanism underlying this side-effect is unclear. The main purposes of the present study were to determine whether cyclosporin A induced the gingival outgrowth by promoting proliferation of gingival cells and whether growth factors such as transforming growth factor-,s (TGF-,s), fibroblast growth factor-2 (FGF-2), platelet-derived growth factors (PDGFs), and insulin-like growth factors (IGFs) are involved in the possible changes in the proliferation of gingival cells induced by cyclosporin A. Methods:, Cells isolated from rat gingival tissues were cultured with cyclosporin A or IGF-I for 3 days. The effects of cyclosporin A or IGF-I on the proliferation of cultured rat gingival cells were analyzed with a CellTiter 96 proliferation assay kit. The mRNA expression levels for TGF-,s, FGF-2, PDGFs, IGFs, insulin-like growth factor receptors (IGFRs), and insulin-like growth factor binding proteins (IGFBPs) in the rat gingival cells treated with cyclosporin A were measured using competitive reverse transcription,polymerase chain reaction (RT,PCR). Results:, Cyclosporin A induced 23,25% (p < 0.001) increases in the proliferation of rat gingival cells and approximately 130% (p < 0.05) and 60% (p < 0.05) elevations in the mRNA expression levels for TGF-,1 and FGF-2, respectively. On the other hand, exogenous IGF-I induced 8,11% (p < 0.05) increases in the proliferation, but cyclosporin A induced 30,80% (p < 0.05,0.01) reductions in the mRNA expression levels for endogenous IGF-I, IGFR1, IGFBP2, IGFBP3, IGFBP5, and IGFBP6. Conclusions:, Cyclosporin A stimulates the proliferation of rat gingival cells. TGF-,1 and FGF-2 could be involved, but IGFs, IGFRs and IGFBPs could not be directly involved in this cyclosporin A induced-stimulation of the gingival cell proliferation. [source] The Effect of Acute Ethanol Intoxication on Salivary Proteins of Innate and Adaptive ImmunityALCOHOLISM, Issue 4 2008Napoleon Waszkiewicz Background:, Human salivary proteins: peroxidase, lysozyme, lactoferrin, and IgA, participate in the protection of oral tissues, as well as upper digestive and respiratory tracts, against a number of microbial pathogens. In the current study, we investigated the effect of acute consumption of a large dose of ethanol on representative human salivary proteins of the innate and adaptive immune systems. Methods:, Eight healthy male volunteers drank an average of 2.0 g (1.4 to 2.5 g/kg) body weight of ethanol, in the form of vodka, in the 6-hour period. Samples of resting whole saliva were collected 12 hours before, then 36 and 108 hours after, the alcohol consumption. The levels of total protein, immunoglobulin A, lysozyme and lactoferrin as well as peroxidase activity were determined in saliva. Results:, At 36 hours after alcohol consumption, salivary protein and lysozyme concentrations as well as peroxidase activity were significantly decreased (p = 0.002, p = 0.043, and p = 0.003, respectively), in comparison to the values obtained at 12 hours before drinking. Between 36 and 108 hours after alcohol consumption, the salivary protein and lysozyme concentrations, as well as peroxidase activity showed a tendency to increase, although at 108 hours after the drinking session, the concentration of protein and peroxidase activity were still significantly lower than before drinking. There was no significant change in the level of lactoferrin, after the drinking session. The salivary concentration of IgA tended to increase at 36 hours after alcohol consumption, and at 108 hours it was significantly higher (p = 0.028), when compared to IgA concentration in the saliva collected before drinking (from 8% to 26% and 32% of total protein content, respectively). Conclusion:, Our report is the first to show that acute ingestion of relatively large, yet tolerable dose of alcohol, significantly disturbs salivary antimicrobial defense system. Reduced lysozyme level and decreased peroxidase activity may contribute to increased susceptibility to infections, when acute alcohol intake coincides with exposure to pathogens. [source] Effects of oral commensal and pathogenic bacteria on human dendritic cellsMOLECULAR ORAL MICROBIOLOGY, Issue 2 2009T. Chino Background/aims:, The oral cavity harbors a diverse and complex microbial community. Bacteria accumulate on both the hard and soft oral tissues in sessile biofilms and engage the host in an intricate cellular dialog, which normally constrains the bacteria to a state of commensal harmony. Dendritic cells (DCs) are likely to balance tolerance and active immunity to commensal microorganisms as part of chronic inflammatory responses. While the role played by DCs in maintaining intestinal homeostasis has been investigated extensively, relatively little is known about DC responses to oral bacteria. Methods:, In this study, we pulsed human monocyte-derived immature DCs (iDCs) with cell wall extracts from pathogenic and commensal gram-positive or gram-negative oral bacteria. Results:, Although all bacterial extracts tested induced iDCs to mature and produce cytokines/chemokines including interleukin-12p40, tumor necrosis factor-,, and monocyte chemoattractant protein-1 (MCP-1), the most important factor for programming DCs by oral bacteria was whether they were gram-positive or gram-negative, not whether they were commensal or pathogenic. In general, gram-negative oral bacteria, except for periodontopathic Porphyromonas gingivalis, stimulated DC maturation and cytokine production at lower concentrations than gram-positive oral bacteria. The threshold of bacteria needed to stimulate chemokine production was 100-fold to 1000-fold lower than that needed to induce cytokines. In addition, very low doses of oral commensal bacteria triggered monocytes to migrate toward DC-derived MCP-1. Conclusion:, Oral commensal and pathogenic bacteria do not differ qualitatively in how they program DCs. DC-derived MCP-1 induced in response to oral commensal bacteria may play a role, at least in part, in the maintenance of oral tissue integrity by attracting monocytes. [source] Salivary mucin as related to oral Streptococcus mutans in elderly peopleMOLECULAR ORAL MICROBIOLOGY, Issue 1 2000L. W. Baughan MG1 (MUC5b and MUC4 ) and MG2 (MUC7), predominant mucins in human whole saliva, provide lubrication and antimicrobial protection for oral tissues. This study examines potential relationships between Streptococcus mutans titers in the oral cavity and the following: mucin concentrations; unstimulated and stimulated whole saliva flow rates; decayed, missing, and filled tooth surfaces; and age of 24 elderly patients. S. mutans titers were determined using Denticult SM. Mucin concentrations were determined using Stains-all, sodium dodecyl sulfate,polyacrylamide gel electrophoresis. Logistic regression was used to identify potential relationships between the above variables. S. mutans classification served as the dependent variable. The remaining variables were possible predictor variables. The best model for predicting S. mutans category contained log MG2 as a predictor variable for all of its parameter estimates. No other set of parameter estimates were statistically significant. These results suggest that elevated S. mutans titers are significantly associated with diminished concentrations of MG2 in unstimulated whole saliva, as quantified in mucin-dye binding units. [source] Cells from bone marrow that evolve into oral tissues and their clinical applicationsORAL DISEASES, Issue 1 2007OM Maria There are two major well-characterized populations of post-natal (adult) stem cells in bone marrow: hematopoietic stem cells which give rise to blood cells of all lineages, and mesenchymal stem cells which give rise to osteoblasts, adipocytes, and fibroblasts. For the past 50 years, strict rules were taught governing developmental biology. However, recently, numerous studies have emerged from researchers in different fields suggesting the unthinkable , that stem cells isolated from a variety of organs are capable of ignoring their cell lineage boundaries and exhibiting more plasticity in their fates. Plasticity is defined as the ability of post-natal (tissue-specific adult) stem cells to differentiate into mature and functional cells of the same or of a different germ layer of origin. There are reports that bone marrow stem cells can evolve into cells of all dermal lineages, such as hepatocytes, skeletal myocytes, cardiomyocytes, neural, endothelial, epithelial, and even endocrine cells. These findings promise significant therapeutic implications for regenerative medicine. This article will review recent reports of bone marrow cells that have the ability to evolve or differentiate into oral and craniofacial tissues, such as the periodontal ligament, alveolar bone, condyle, tooth, bone around dental and facial implants, and oral mucosa. [source] Oral cancer awareness for the general practitioner: new approaches to patient careAUSTRALIAN DENTAL JOURNAL, Issue 1 2008CS Farah Abstract In Australia, oral cancer accounts for approximately 2,3 per cent of all cancers, and approximately 1 per cent of deaths from cancer. The incidence of intra-oral cancer is gradually increasing. It is now well established that early detection of potentially malignant disease can improve the clinical outcome for patients, and as such it is the responsibility of dentists to identify such lesions early. To facilitate early detection of suspicious oral lesions several clinical methods of detection can be used. In addition to conventional visual screening of oral tissues with the naked eye under projected incandescent or halogen illumination, there are many clinical diagnostic aids that can be undertaken to help detect oral cancer. In this article we explore clinically available modalities that may be used by the general dental practitioner, and highlight their inherent strengths and weaknesses. [source] | ||||||||||