Differential expression of Toll-like receptors in chronic hyperplastic candidosis.

INTRODUCTION: The first step in the host defense against oral candidosis is the recognition of Candida albicans through a set of germ-encoded pathogen recognition receptors, e.g. Toll-like receptors (TLRs). In man, 10 types of such receptors have been identified so far, of which only TLR2, TLR4, and TLR6 have been linked to mediating candidal ligands, e.g. zymosan. METHODS: Biopsies from patients with chronic hyperplastic candidosis (n = 5), leukoplakia (n = 5), and healthy mucosa (n = 5) were immunohistochemically stained with antibodies to the TLRs (TLR1 to TLR9) to distinguish and compare the staining patterns of the epithelial layer in the three categories of tissues. RESULTS: On analysis, the epithelium of all tissues was divided into three layers: basal, middle, and superficial. Two of the five chronic hyperplastic candidosis sections showed high numbers of hyphae compared to yeasts, which paralleled a decrease in the expression of TLR2 and an increase in the staining intensity of TLR4. Leukoplakia and healthy tissue sections demonstrated stronger immunostaining of TLRs, except TLR9 which showed weaker staining in some sections of the former, and in the basal layers of some sections of the latter. DISCUSSION: This study supports the concept of negative regulation of TLRs that are either ligand-bound (e.g. in chronic hyperplastic candidosis), or not stimulated (in healthy tissue). It also augments the opinion that C. albicans, through its hyphae rather than blastospore, may utilize TLRs, i.e. TLR2, to evade the immune system of the host. Leukoplakia seems to be more immunologically alert, which reduces the chances of worsening the already-diseased tissue.

Disruption of the blood-brain barrier during TNBS colitis.

Well-documented central nervous system changes during colitis suggest possible alterations of blood-brain barrier (BBB) permeability, yet the integrity of the BBB has not been fully evaluated in experimental colitis. Our aim was to investigate whether trinitrobenzene sulphonic acid (TNBS) colitis was associated with an increase in the permeability of the BBB. Sprague-Dawley rats were given an intracolonic injection of saline or TNBS and studied 1, 2, 3, 7 and 21 days after treatment. The extravasation of endogenous immunoglobulin G, a large molecule, was not altered at any time after TNBS treatment. In contrast, significant increases in the BBB leakage of sodium fluorescein, a much smaller molecule, were observed 1 and 2 days after the induction of colitis, in and around the circumventricular organs; the organum vasculosum of the lamina terminalis, subfornical organ and median eminence of the hypothalamus. TNBS-treated rats also exhibited sodium fluorescein leakage in focal areas in the brain parenchyma. The expression of endothelial barrier antigen, a protein associated with the BBB, was reduced about 60% 48 h after the induction of colitis. This returned to control values by 3 weeks, when colitis had largely subsided. In conclusion, experimental colitis transiently increased permeability of the brain to small molecules through a mild disruption of the BBB.

Metabolic response to lactitol and xylitol in healthy men.

Sugar alcohols are used in food products, yet their metabolic effects in humans are poorly known. We examined plasma glucose, insulin, and C-peptide responses and changes in carbohydrate and lipid oxidation after the ingestion of 25 g lactitol, xylitol, or glucose. Eight healthy, nonobese men were studied after an overnight fast. After the ingestion of lactitol or xylitol, the rise in plasma glucose, insulin, and C-peptide concentrations was less than after the ingestion of glucose (P < 0.02), with no difference between the two polyols. With the glycemic index of glucose as 100, the indexes of xylitol and lactitol were 7 and -1, respectively. A reactive hypoglycemia was observed 3 h after glucose ingestion, but not after the ingestion of sugar alcohols. There were no significant changes in the carbohydrate or lipid oxidation as determined by indirect calorimetry after the ingestion of sugar alcohols. After glucose ingestion, the rise in carbohydrate oxidation was nearly significant (P = 0.07). In conclusion, lactitol and xylitol cause smaller changes than does glucose in plasma glucose and insulin concentrations and thermogenic response. A small hormonal response and the lack of a thermogenic effect may be beneficial when these sugar alcohols are used in food products. The small glucose and insulin responses also suggest that lactitol and xylitol are suitable components of the diet for diabetic patients.

Tumor necrosis factor-alpha (TNF-alpha) in loosening of total hip replacement (THR).

OBJECTIVE: The initially well-fixed implants of total hip replacement (THR) are in the long-term subject to aseptic loosening. Many cytokines can contribute to osteolysis due to osteoclast recruitment and/or activation. However, in this respect tumor necrosis factor-alpha (TNF-alpha) plays a pivotal role, because it upregulates interleukin-1 and 6 and granulocyte-macrophage colony stimulating factor. The aim of this study was to assess the eventual presence, cellular localization and extent of expression of TNF-alpha in the synovial-like membrane at the implant or at the cement to bone interface compared to control synovial membrane. METHODS: Twenty samples from the synovial-like membrane of the periprosthetic tissues were compared to control samples. TNF-alpha containing cells were visualized using an avidin-biotin-peroxidase complex (ABC) method and analyzed by light microscopy, double labelling and image analysis. RESULTS: TNF-alpha was found in the periprosthetic tissues in fibroblasts and vascular endothelial cells, but mainly in the macrophages was it found to coincide with areas containing implant-derived debris. TNF-alpha containing cells were more numerous in the synovial-like membrane in the interface tissue from the proximal stem area (2816 +/- 318 cells) than in the control synovial membrane (565 +/- 93 cells, p < 0.01). Interestingly, similarly high TNF-alpha expression (3452 +/- 582 cells) was also seen in the synovial-like membrane of the pseudocapsule. CONCLUSION: These findings suggest that the foreign body-type host reaction caused by THR is characterized by the high expression of TNF-alpha. Because such expression occurred in the interface tissue between the implant and surrounding bone, TNF-alpha, due to its pivotal direct and indirect role in the activation and recruitment of osteoclasts, may contribute to periprosthetic osteolysis and to the loosening of THR.

Recurrent aphthous ulcers today: a review of the growing knowledge.

Recurrent aphthous ulcers represent a very common but poorly understood mucosal disorder. They occur in men and women of all ages, races and geographic regions. It is estimated that at least 1 in 5 individuals has at least once been afflicted with aphthous ulcers. The condition is classified as minor, major, and herpetiform on the basis of ulcer size and number. Attacks may be precipitated by local trauma, stress, food intake, drugs, hormonal changes and vitamin and trace element deficiencies. Local and systemic conditions, and genetic, immunological and microbial factors all may play a role in the pathogenesis of recurrent aphthous ulceration (RAU). However, to date, no principal cause has been discovered. Since the aetiology is unknown, diagnosis is entirely based on history and clinical criteria and no laboratory procedures exist to confirm the diagnosis. Although RAU may be a marker of an underlying systemic illness such as coeliac disease, or may present as one of the features of Behcet's disease, in most cases no additional body systems are affected, and patients remain otherwise fit and well. Different aetiologies and mechanisms might be operative in the aetiopathogenesis of aphthous ulceration, but pain, recurrence, self-limitation of the condition, and destruction of the epithelium seem to be the ultimate outcomes. There is no curative therapy to prevent the recurrence of ulcers, and all available treatment modalities can only reduce the frequency or severity of the lesions.

Increased density of lymphocytes bearing gamma/delta T-cell receptors in recurrent aphthous ulceration (RAU).

Lymphocytes bearing the T-cell receptor (TCR) gamma/delta are increased in the peripheral blood of patients with recurrent aphthous ulcers (RAU) and Behcet's disease. In this study, we examined whether the density of TCR-gamma/delta bearing lymphocytes was also increased locally in RAU lesions. Ten RAU lesions from ten patients were compared with ulcer-free mucosa from sites contralateral to the lesions, and with 10 samples of clinically healthy oral mucosa taken from 10 healthy volunteers. Samples were labeled with a panel of monoclonal antibodies specific to CD3, alpha/beta TCR and gamma/delta TCR in avidin-biotin-peroxidase complex (ABC) staining. Lymphocytes expressing gamma/delta TCRs were very low in non-lesional mucosa and clinically healthy mucosa. By contrast, gamma/delta T-cells were numerous and observed in all RAU lesions especially within the epithelium, inflammatory infiltrates and at perivascular locations. The count of gamma/delta T-cells was high in connective tissue of RAU (200 +/- 126 cells/mm2) compared with connective tissue of controls (4+/-4 cells/mm2; P<0.0001) or non-lesional mucosa (5+/-7 cells/mm2). Interestingly, the density of gamma/delta T-cells was also high in the epithelium of RAU (70+/-34 cells/mm2) compared with the epithelium of non-lesional mucosa (2.8+/-06 cells/mm2; P<0.0001) or epithelium of healthy controls (1.2+/-1.5 cells/mm2; P<0.0001). Moreover, the mean percentage of gamma/delta+ T-cells among total CD3+ lymphocytes was increased in the connective tissue area from 4% and 5% in controls and non-lesional mucosa, respectively, to 19% in RAU. In epithelial areas, the average percentage was increased from 2% and 6% in controls and non-lesional mucosa, respectively, to 36% in RAU. These data showed that gamma/delta T-cells are more numerous in RAU lesions and such an increase was purely restricted to RAU inflammatory areas.

Immunolocalization of tumor necrosis factor-alpha expressing cells in recurrent aphthous ulcer lesions (RAU).

Tumor necrosis factor (TNF)-alpha is a pro-inflammatory cytokine and crucial mediator in many aspects of immunity. Although several studies have shown that recurrent aphthous ulcers (RAU) can be prevented by treatment that prevents the synthesis of endogenous TNF-alpha little is known about the location and distribution of TNF-alpha-expressing cells at disease sites. The aim of the present work is, therefore, to investigate TNF-alpha and its cellular distribution in RAU lesions compared with those in induced oral traumatic ulcers (TUs). Twelve biopsies of RAU lesions of oral mucosa were obtained from 12 patients with RAU. They were compared to a control group consisting of ten samples of induced TUs. All samples were analyzed for TNF-alpha expression by using monoclonal mouse anti-human TNF-alpha antibody in avidin-biotin-peroxidase complex (ABC) staining. Results were quantified by a semi-automatic VIDAS image analysis system. TNF-alpha immunoreactivity was contained mainly in monocyte/macrophages and lymphocytes within the mononuclear inflammatory infiltrates. TNF-alpha was often seen in mast cells and vascular endothelial cells in connective tissue lateral to the inflammatory infiltrates. Interestingly, 32%-60% of the mononuclear cells were found to be TNF-alpha immunoreactive in RAU lesions. TNF-alpha containing cells were more numerous in aphthae (188+/-46 cells/0.2 mm2) compared with controls (52+/-14 cells/0.2 mm2, P<0.001). These findings suggest that RAU lesions are characterized by high expression of TNF-alpha. Because such expression occurred in the mononuclear inflammatory cells, mast cells and vascular endothelial cells, TNF-alpha, which is a major inflammatory mediator, may contribute to the activation and recruitment of leukocytes that are found in RAU lesions.

Quantitative assessment of mast cells in recurrent aphthous ulcers (RAU).

Previous studies on the frequency of mast cells (MCs) in recurrent aphthous ulcers (RAU) have yielded conflicting results. Monoclonal antibodies specific for tryptase (AA1) and anti-IgE (polyclonal antibody) were used to identify density and distribution of MCs in an immunohistochemical study of RAU (n=15), induced oral traumatic ulcers (TUs) (n=9), and control clinically healthy oral mucosa (n=15). Results were quantified by means of a VIDAS image analyzer. In all sections studied, IgE-positive cells showed similar frequency and distribution to tryptase-positive MCs. In RAU lesions, numerous tryptase-positive MCs were found in the sub-epithelial lamina propria, but MC numbers in the epithelium were low and present only in some RAU biopsies. MCs were also more numerous in RAU-inflammatory infiltrates (118+/-31 cells/mm2) than those seen in TU-inflammatory infiltrates (75+/-18 cells/mm2, P<0.001). MC activation/degranulation, as judged by diffuse extracellular tryptase staining, was a common feature within RAU-inflammatory infiltrates and at RAU-inflammatory infiltrates-connective tissue interfaces, which were often associated with connective tissue disruption. MC counts in the RAU connective tissue, lateral to the inflammatory infiltrates, were significantly greater than in the connective tissue of TUs and of control biopsies (124+/-36 vs 73+/-13 vs 69+/-21 cells/mm2, respectively; P<0.001). Overall, MCs were significantly increased in aphthae (116+/-26 cells/mm2) compared with TU lesions (72+/-11 cells/mm2, P<0.001) and controls (71+/-16 cells/mm2, P<0.001). In conclusion, MC numbers are increased in a typical topographical pattern, and the local MCs show signs of activation/degranulation suggesting active involvement of this cell type in RAU pathogenesis.

Factor XIIIa-positive dendrocytes are increased in number and size in recurrent aphthous ulcers (RAU).

The factor XIIIa-positive (FXIIIa+) cell is a potent antigen-presenting cell, which has been described as increasing in numbers in various chronic inflammatory conditions. The purpose of this study was to investigate the distribution and frequency of FXIIIa+ cells in acute recurrent aphthous ulcer (RAU) lesions compared with induced traumatic ulcer (TU) lesions and with clinically healthy oral mucosa. Samples were labeled with polyclonal rabbit anti-human FXIIIa antibodies in avidin-biotin-peroxidase complex (ABC) staining. Most of the FXIIIa-immunoreactive cells in TUs and normal mucosa were spindle-shaped, whereas a relatively large, dendritic-like cell was predominant in RAU lesions. FXIIIa+ cells were quite frequent within mononuclear cell-rich inflammatory cell infiltrates and in perivascular areas in RAU lesions. In contrast, FXIIIa+ cells were not found in mucosal epithelium or in the neutrophil-rich areas. RAU mononuclear cell-rich inflammatory cell infiltrates appeared to have greater numbers of positively stained cells than the TU-inflammatory cell infiltrates (199 +/- 67 vs 110 +/- 31 cells/mm2, P < 0.001). Overall, FXIIIa+ dendrocytes were increased in numbers, and apparently also in size, in RAU lesions (274 +/- 68/mm2) as compared to controls (177 +/- 74/mm2, P < 0.01), and to TU lesions (183 +/- 50 mm2, P < 0.01). Interestingly, relatively high numbers of FXIIIa+ dendrocytes were also found in deep connective tissue in RAU sections compared with TUs (281 +/- 80 vs 166 +/- 57, P < 0.01). The characteristic changes in the size and shape of individual FXIIIa+ cells, their typical distribution and increase in frequency in RAU lesions indicate active involvement in the local pathogenic mechanisms. Localization to perivascular areas/inflammatory cell infiltrates would be compatible with a role in antigen presentation.

Salivary gland scintigraphy in Sjögren's syndrome and patients with sicca symptoms but without Sjögren's syndrome: the psychological profiles and predictors for salivary gland dysfunction.

OBJECTIVE: To characterise the psychological profiles of Sjögren's syndrome (SS) and patients with sicca symptoms but without SS; to find predictors for salivary gland function; to evaluate salivary scintigraphy as a method to differentiate between SS and patients with sicca symptoms but without SS. PATIENTS AND METHODS: Psychological tests (Medical Outcomes Study Short Form General Health Survey (SF-36), Jenkins Activity Survey, Toronto Alexithymia Scale, and Maastricht Questionnaire for vital exhaustion) were performed and assessment of the function of the salivary glands made in 26 patients with primary SS, 8 with secondary SS, and 9 with sicca symptoms but without SS. Data were analysed with BMDP new system version 1.0 statistical program. RESULTS: Psychological profiles were similar in all groups. Hb, RF, ANA, and SSA differentiated between the groups. Results of salivary scintigraphy were predicted to 51% by ANA, SSA, SSB, IgG, IgA, diagnosis, vitality, and role limitations due to emotional problems. No predictors were found for the resting salivary flow. Salivary scintigraphy was pathological in 21/26 (81%) and in 8/8 (100%) patients with secondary SS, but only in 2/9 (22%) patients with sicca symptoms without SS (p=0.002) (sensitivity 85.3%, specificity 77.8%). CONCLUSIONS: Patients with sicca symptoms but without SS have sickness behaviour similar to that of patients with SS. The results of salivary scintigraphy can be predicted by diagnosis and autoimmune findings; psychological characteristics added 20% to this predictive value. Distinction between SS and patients with sicca symptoms but without SS is difficult, but in addition to autoantibodies, salivary scintigraphy can be used for this purpose.