Elucidating role of salivary proteins in denture stomatitis using a proteomic approach

Denture stomatitis (DS) is the most common oral pathology among denture wearers, affecting over one-third of this group. DS is usually associated with C. albicans. However, unlike other oral candidiasis, most DS patients have intact host immunity. The presence of a denture alone is usually sufficient for DS. Saliva and its protein contents can theoretically predispose some denture wearers to DS and others resistant toward DS. Here we proposed for the first time to define salivary proteomic profiles of denture wearers with and without DS. SELDI-TOF/MS analysis suggests that there is a proteomic differentiation among control, localized and generalized DS. Based on initial SELDI-TOF/MS profiling, we further used reversed phase liquid chromatography, MALDI-TOF/MS, and LC-MS/MS to characterize the salivary proteins associated with DS. Nineteen proteins based on SELDI-TOF/MS profiling were found including cystatin-SN, statherin, kininogen-1, desmocollin-2, carbonic anhydrase-6, peptidyl-prolyl cis-trans isomerase A like peptides, cystatin C, and several immunoglobulin fragments. The proteomic content gives evidence of the interaction between host tissue, saliva, and candida. Further examination in larger populations of these proteins may help to gain a better understanding of DS pathological processes and improve DS treatments.

[Immunological aspects of pathogenesis of stomatological constructional materials intolerance]

In blood and the mixed saliva of patients with intolerance of stomatologic constructional materials the maintenance of cytokines, factors of humoral answer were investigated. It was established, that in formation of intolerance the increased sensitivity stomatologic constructional materials which is not connected to allergic reaction of immediate type and is, apparently, pseudoallergic or develops on other type. There is an activation of the local immune answer including local synthesis of proinflammatory cytokines, sIgA and hyperactivation of complement system to formation of C3a component. Toxic and allergic action of stomatologic constructional materials grows in patients having antibodies to Candida albicans in the mixed saliva.

Serum itraconazole concentrations and clinical responses in Candida-associated denture stomatitis patients treated with itraconazole solution and itraconazole capsules

The aim of this study was to compare the concentrations of itraconazole in serum and saliva after treatment with itraconazole cyclodextrin solution or itraconazole capsules in Candida-associated denture stomatitis patients without evidence of immunodeficiency. Forty patients were randomly assigned to receive either itraconazole cyclodextrin solution or itraconazole capsules, both at a dosage of 100 mg bd for 15 days. On completion of treatment palatal erythema was assessed and an oral rinse and imprint cultures were collected. Serum and saliva samples were collected at the same time and itraconazole concentrations measured using reverse-phase high-performance liquid chromatography. Itraconazole susceptibilities of Candida albicans and Candida glabrata strains isolated at baseline were measured by a broth microdilution method. Serum itraconazole concentrations achieved did not differ significantly between the two preparations (P = 0.39) although a significantly higher number of patients in the itraconazole cyclodextrin group (P < 0.001) had detectable levels of itraconazole in their saliva compared with the capsule group. Mycologically cured patients had slightly, though not significantly (P = 0.28), higher serum itraconazole concentrations than those from whom yeasts were not eradicated. It was concluded that both formulations of itraconazole were equally effective in treatment of denture stomatitis. Among immunocompetent patients, the absorption of the liquid preparation is no greater than that of the capsules. Therapeutic success in this group was achieved with lower serum itraconazole concentrations than have been reported for immunocompromised groups.

Expression of p53 in oral mucosal hyperplasia, dysplasia and squamous cell carcinoma

OBJECTIVE

To assess p53 expression in a range of oral mucosal lesions and to relate the results to the clinical outcome in patients with dysplastic oral mucosal lesions and oral squamous cell carcinomas (OSCC).

MATERIALS AND METHODS

Archival tissue was available for eight cases of normal oral mucosa, 50 cases of oral mucosal hyperplasia, 41 cases of oral mucosal dysplasia and 48 cases of OSCC. The monoclonal antibody DO-7, reactive to p53 protein, was applied to paraffin-embedded sections using microwave pretreatment and immunohistochemical techniques.

RESULTS

The results showed that normal oral mucosa did not express p53. Positive nuclear staining was found in 18/50 (36%) cases of hyperplasia, 35/41 (85%) cases of dysplasia and 45/48 (94%) cases of OSCC. None of the p53 negative dysplasias progressed, while 19% of p53 positive cases of dysplasia recurred following excision and 11% of the cases underwent neoplastic transformation. Five out of 10 (50%) cases of severe dysplasia which were p53 positive resolved.

CONCLUSION

The proportion of cases with positive p53 expression increased from hyperplasia to dysplasia to OSCC. These results may indicate an involvement of p53 in neoplastic transformation as well as in proliferative events although the presence or absence of p53 staining could not be used to predict the outcome of potentially malignant oral mucosal lesions.

Denture stomatitis: quantification of interleukin-2 production by mononuclear blood cells cultured with Candida albicans

Denture stomatitis is usually associated with the presence of yeast, particularly Candida albicans, and several bacteria. In this study mononuclear blood cells were grown in the presence of Candida albicans from a single colony, and interleukin-2 production induced in T lymphocytes was measured. Blood cells were from a population of patients with denture stomatitis and a control group of denture wearers without stomatitis. Induction of interleukin-2 production was correlated with factors that condition denture stomatitis, namely, isolation of Candida albicans in selective medium, age of the denture, and diabetes. Concentrations of interleukin-2 in supernatant and serum were also compared. Significant differences in interleukin-2 production were found between patients with denture stomatitis and controls. Statistical analysis demonstrated a significant association between isolation of Candida albicans and elevated interleukin-2 production in cultures from patients with and without denture stomatitis.

Fatty acid composition of palatal tissue from denture stomatitis patients

Palatal biopsy specimens were obtained from patients with denture stomatitis. The fatty acids were extracted from the tissue, then separated, identified, and quantified by a gas-chromatographic technique. The sensitivity of this method enabled analyses of specimens with a wet weight of less than 1 mg. The concentration of the fatty acids C16:1 (n-7) and C24:1 (n-9) differed significantly between samples from hyperplastic and clinically healthy tissue in the denture stomatitis patients. By comparing specimens from denture stomatitis patients and non-denture subjects, the concentration of seven fatty acids, two saturated and five unsaturated, was found to be significantly different. A multivariate data-analytical method distinguished between the fatty acid composition in specimens from denture stomatitis patients and from non-denture subjects.

Enhanced cytokine production and collagen synthesis of gingival fibroblasts from patients with denture fibromatosis

The mechanisms of denture-induced gingival hypertrophy remain to be explored. Since fibroblast proliferation and bone resorption characterize this disorder, the possible involvement of cytokines was investigated. Gingival fibroblasts were obtained from six patients with denture fibromatosis (Den-Fb) and six healthy persons (Nor-Fb). Cells were compared for proliferation, collagen synthesis, and cytokine production. Incorporation of [3H]thymidine (TdR) was increased in 3 Den-Fb and 3 Nor-Fb lines in the presence of interleukin-1-beta (IL-1 beta) (10 U/mL) and tumor necrosis factor-alpha (TNF-alpha) (from 10 to 100 U/mL). Proline incorporation in Den-Fb was higher than that in Nor-Fb, and the mean collagen synthesis level in Den-Fb was significantly higher than that in Nor-Fb. Although there was no difference between the up-regulation of protein synthesis in Den-Fb and Nor-Fb induced by IL-1 beta or TNF-alpha, the receptors for these cytokines were expressed at higher levels in cell lines which exhibited higher protein synthesis. Between Nor-Fb and Den-Fb, there was no difference in the generation of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-6 (IL-6). However, most Den-Fb produced more GM-CSF and IL-6 in the presence of TNF-alpha. Enhancement of IL-6 generation by GM-CSF was also more prominent in Den-Fb. GM-CSF and IL-6 were synergistically generated after co-culture of the fibroblasts with gingival keratinocytes. GM-CSF and IL-6 generation of Den-Fb was markedly enhanced by co-culture of Den-Fb with peripheral blood mononuclear cells (PBMC), especially PBMC from patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of acquired denture pellicle from healthy and stomatitis patients

Little information is available about the acquired pellicle layer that is formed on denture surfaces or its role in regulating microbial colonization of the prosthetic surface. Because denture-induced stomatitis is associated with increased numbers of Candida albicans and other microorganisms on the denture surface, the acquired denture pellicle (ADP) may play a role in modulating this colonization. This study examined and compared ADP from healthy patients and patients with stomatitis by chemical and immunochemical methods. The ADP was found to be composed of a selectively adsorbed layer containing salivary amylase, high molecular weight mucin (MG1), lysozyme, albumin, and sIgA. Salivary cystatins, proline-rich proteins, and low molecular weight mucin (MG2) were not detected. ADP amino acid composition was distinct from any of the ductal salivas, but had many similarities with enamel pellicle. Immunoblots of ADP from patients with stomatitis identified additional serum components, degradation products, and C. albicans cell components that were not detected in ADP from healthy patients. Quantification of these molecules in ADP could lead to a diagnostic test for oral mucosal disease underlying a denture base. Identification of specific molecules in denture pellicle that promote adhesion of C. albicans may elucidate a mechanism of fungal cell colonization on the denture surface. Future studies that chemically modify the denture acrylic resin surface to immobilize antimicrobial proteins may be a means of decreasing pathogenic plaque development.

Barrier properties of inflamed denture-loaded palatal mucosa to water

The barrier property of inflamed palatal mucosa to water has been studied in eight adult edentulous persons with a generalized denture stomatitis, by measuring the transmucosal water flow under varying osmotic gradients. Flow rates were registered gravimetrically in solute saturated filter paper discs after 10-min periods of mucosal contact, using solutions with an osmolarity of 0, 0.25, 0.30, 0.38, 0.50 and 0.75 osmol sucrose/l. The histology of the mucosal areas was evaluated from cytologic scrapings, and biopsy material from two persons. The inflow with use of pure water was 2.98 mg/cm2/10 min, being about three and a half times greater than through the intact mucosal surface. The point of isotony of the inflamed mucosa ranged between 0.30 and 0.36 with a mean value of 0.33 osmol/l, thus being of the same magnitude as in plasma and tissue fluid. The observations from the biopsy material were in accordance with earlier histological evidence from generalized denture stomatitis, indicating that the permeability properties of the inflamed mucosa belonged to epithelial cell layers located in the lower part of the spinous layer.

Denture stomatitis-yeast occurrence and the pH of saliva and denture plaque

The study comprised 30 denture wearers with generalized simple or granular inflammation in the palate and 30 without (controls). )easts, mostly Candida species, were cultivated from the maxillary dentures of all subjects with inflammation and of 23 controls. Hyphae were found in the maxillary denture smears from 28 subjects with inflammation and from 18 controls. Thus it seems unjustified to consider the occurrence of hyphae pathognomonic of denture stomatitis. The pH of whole saliva did not differ in the two groups (inflammation:mean pH 6.5, control:6.6). There was no clear relation between the pH of resting saliva and the amount of fungal cultures. Thirty minutes after a mouthrinse with 10 ml of a 25% sucrose solution, the mean saliva pH had dropped equally in both groups. With regard to the denture plaque, samples taken 40 min after the rinse indicated a more pronounced acid production in the plaque associated with inflammation. The pH of "resting" plaque was also lower in the inflammation than in the control group (mean maxillary pH 5.7 and 6.3 respectively, a=0.002). No association was found between the pH and the occurrence of hyphae in "resting" denture plaque. This supports the view that the pH is of no major importance for filamentation in vivo.

Changes in the water permeability of palatal mucosa after complete denture treatment

The water permeability of the human palatal mucosa has been studied in 12 persons with 1 year of full maxillary denture experience and 10 persons without dentures. Transmucosal water transport rates were studied gravimetrically with the use of solutesaturated discs of filter paper in contact with the mucosa, in accordance with earlier described procedures (KAABER 1973a, b). The inflow of water through clinically healthy mucosa was at the same level in both groups. After use of a 1.10 mol sucrose solution a significant increase in the inflow was observed in the denture wearers group, which suggested an increased amount of osmolytes in the mucosal surface. Two denture wearers with a slightly inflamed mucosal surface showed an increased inflow after use of water and a corresponding strong outflow after use of the sucrose solution, indicating a partial loss of the mucosal barrier function.

Assessment of denture plaque pH in subjects with and without denture stomatitis

To evaluate the "resting" pH and induced pH changes in denture plaque, soft deposits were collected from the fitting surface of the denture, pooled and suspended in water. Plaque pH was determined with microelectrode equipment before and after mouth rinsing with a sucrose solution. A characteristic level in the "resting" pH of denture plaque was found in most of 12 subjects tested. pH values below the baseline level were recorded for more than 2 h after a rinse. The pH depressions were more pronounced in maxillary than in mandibular plaque. Further, the pH minima tended to be lower in subjects with denture stomatitis than in controls. No clear relationship could be established between the "resting" pH and the concentration of Candida hyphae in denture smears or palatal inflammation.