Exploring the association between oral health literacy and alexithymia.

UNLABELLED: Low health literacy and alexithymia have separately been emphasized as barriers to patient-practitioner communication, but the association between the two concepts has not been explored. OBJECTIVE: To test the hypothesis that low oral health literacy and alexithymia are associated. METHOD: Adults (n=127) aged 21-80 years (56% women) participated in this cross-sectional study. Oral health literacy was assessed using the interview-based Adult Health Literacy Instrument for Dentistry (AHLID) with scores from 1-5. The self-administered Toronto Alexithymia Scale (TAS-20) was used to assess three distinct TAS-20 factors and TAS-20 total score. RESULTS: Significant negative correlations between AHLID scores and TAS-20 factors 2, 3 and TAS-20 total score were found. Regression analyses showed that TAS-20 factor 3, externally-oriented thinking (ß=-0.21, SE=0.02, p=0.017), and TAS-20 total score (ß=-0.18, SE=0.01, p=0.036) were significant predictors of AHLID level. CONCLUSION: The hypothesis that low oral health literacy is associated with alexithymia was supported. This finding proposes that alexithymia may be considered as a possible factor for low oral health literacy. However, the correlations are not strong, and the results should be regarded as a first step to provide evidence with additional research on this topic being needed.

Effects of binding of ligand (FVIIa) to induced tissue factor in human endothelial cells.

The tissue factor protein is structurally related to the cytokine receptors and ligand binding (factor VIIa) has been reported to give an intracellular calcium signal, thus indicating that tissue factor is a true receptor. In view of the attempts to use recombinant factor VIIa as a therapeutic agent in hemophilia, its binding effects may be of clinical interest. We have studied the effect of ligand binding to human endothelial cells that were stimulated with interleukin-1 to express tissue factor. Human umbilical cord vein endothelial cells produce and release a wide variety of proteins that participate in coagulation and fibrinolysis, and we have investigated whether binding of recombinant factor VIIa to tissue factor altered the release of some of these compounds. Three main findings are reported. (1) After an initial increase, the measurable tissue factor activity in endothelial cells decreased more rapidly in the presence of factor VIIa (half-life 3.7+/-0.7 hours) than in its absence (half-life 7.4+/-1.5 hours). This difference was not seen when tissue factor antigen was measured, indicating that ligand binding did not increase the degradation of the protein. (2) Tissue factor pathway inhibitor was detected on the cell surface, in cell homogenates, and in cell medium. When recombinant factor VIIa was added to the cells there was a significant decrease in the release of tissue factor pathway inhibitor to the medium. Four hours after recombinant factor VIIa was added, the levels were 7.5-fold higher in the medium of untreated cells compared to the medium of cells treated with recombinant factor VIIa. (3) We observed increased release of von Willebrand factor (vWF). After 1 and 6 hours with recombinant FVIIa the release was significantly greater than in controls without FVIIa. We did not detect significant differences in the release of tissue plasminogen activator or tissue factor pathway inhibitor.

Induction of tissue factor synthesis in human umbilical vein endothelial cells involves protein kinase C.

Incubation of human umbilical vein endothelial cells with one of the following compounds: endotoxin, recombinant interleukin-1 beta, recombinant tumor necrosis factor alpha, allogenic lymphocyte subpopulations or phorbol ester resulted in significant induction of tissue factor synthesis. Diacylglycerol had the same effect and also enhanced synergistically the induction caused by endotoxin and interleukin-1 beta. Two different inhibitors of protein kinase C, H7 and sphingosine, inhibited tissue factor synthesis at concentrations which did not depress protein synthesis in general, suggesting that protein kinase C is involved in the processes leading to tissue factor synthesis. Cells down-regulated for the tissue factor response to TPA responded essentially normally to endotoxin and interleukin-1 with regard to tissue factor synthesis.

Toxicity of sitosterol to human umbilical vein endothelial cells in vitro.

The pathogenesis of the early development of atherosclerosis in sitosterolaemia is unknown. The effect of sitosterol on vascular endothelial cells in vitro was investigated by culturing human umbilical vein endothelial cells in the presence of up to 0.7 mmol l-1 of sitosterol. Liposomes were used to supply the high sterol concentrations. Exposure to 0.7 mmol l-1 of sitosterol for 72 h caused contraction of the endothelial cells and increased release of intracellular lactate dehydrogenase. After 96 h incubation the cells were partly detached from the substrate. At this time-point 0.35 mmol l-1 of sitosterol also caused perturbation of the endothelial cells. However, we could not confirm previous reports that tissue plasminogen activator production was enhanced by sitosterol.

Toxicity of oxygenated cholesterol derivatives toward cultured human umbilical vein endothelial cells.

Human umbilical vein endothelial cells were cultured in the presence of several oxygenated cholesterol derivatives that are known to affect the viability of other cell lines. 5-Cholestene-3 beta,7 beta-diol (7 beta-hydroxycholesterol) caused a time- and concentration-dependent perturbation of the endothelial cells. Exposure to 50 mumol/l of this compound for 18 hours resulted in marked contraction of the cells, followed by increasing cell detachment from the substrate and Trypan Blue uptake in detached cells. Concomitantly release of lactate dehydrogenase from the cells reached about 80% at 24 hours. The release of tissue plasminogen activator and tissue plasminogen activator inhibitor-1 antigens decreased at a concentration of 7 beta-hydroxycholesterol lower than that required for reducing general protein synthesis. 7 beta-Hydroxycholesterol at 50 mumol/l first increased the release and then (at 100 mumol/l) inhibited the synthesis of von Willebrand factor. Incubation with 100 mumol/l of 5-cholestene-3 beta, 7 alpha,22(R)-triol (7 alpha,22-dihydroxycholesterol)e and the isomeric 5-cholestene-3 beta, 7 beta, 22(R)-triol (7 beta, 22-dihydroxycholesterol) caused formation of intercellular gaps and some detachment of the cells after 24 hours. Cell injury was slightly more pronounced for the 7 alpha, 22-dihydroxycholesterol than for the 7 beta-isomer. Incubations with cholesterol under the same conditions gave no sign of cell injury.

Observations on the cell biology of tissue factor in endothelial cells.

Human umbilical vein endothelial cells (HUVEC) are inducible for tissue factor (TF) activity in culture. Based on experiments using ECGF (4-20 micrograms/ml) with heparin (90 micrograms/ml), we obtained the following results: 1) In confluent HUVEC cultures, ECGF had essentially no influence on the levels of inducible TF. 2) In growing HUVEC cultures, ECGF reduced the TF response shortly after seeding but full response was regained when cells were kept confluent for 2-3 days. 3) Although secondary cultures responded best to TF induction in the absence of ECGF, the response was essentially equal over at least 8 passages in the presence of ECGF. 4) Of total cellular TF induced in HUVEC, about 25% was available on the surface, and less than 4% was released with the shed plasma membrane vesicles. The proportion of total TF activity available on the surface of intact cells was not influenced by the presence of ECGF. 5) T1/2 for the decay of TF activity induced was 8.3-9.5 h, whereas in HUVEC when protein synthesis was blocked after TF induction a T1/2 of about 30 h was found.

Allogenic induction of thromboplastin synthesis in monocytes and endothelial cells. Biphasic effect of cyclosporin A.

Monocytes and endothelial cells were stimulated in co-culture with allogeneic lymphocytes to produce thromboplastin (TPL). The induction was biphasic, an early response (8-24 h) was greatly augmented by cyclosporin A (CS) (0.5-5 micrograms/ml) whereas the late response (day 3-4) was inhibited. Prednisolone inhibited both responses. Both drugs inhibited lymphocyte proliferation. Interferon-gamma decreased MLC TPL activity but increased thymidine incorporation. CD4+ cells were instrumental in inducing the early TPL peak in monocytes, whereas CD8+ cells decreased the TPL effect. With endothelial cells both T cell classes were equally effective. Conditioned medium from MLC as well as from co-cultures of endothelial cells and lymphocytes induced early TPL synthesis in endothelial cells. Upon allogeneic stimulation monocytes, but not endothelial cells, produced a significant amount of F-VII, most of which was apparently undercarboxylated.

Synthesis of thromboplastin (tissue factor) by endothelial cells.

Molecular genetics, biochemistry, and cell biology of thromboplastin are briefly reviewed with special emphasis on its biosynthesis by endothelial cells.