Nuclear F-actin Cytology in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Oral cavity cancer has a low 5-y survival rate, but outcomes improve when the disease is detected early. Cytology is a less invasive method to assess oral potentially malignant disorders relative to the gold-standard scalpel biopsy and histopathology. In this report, we aimed to determine the utility of cytological signatures, including nuclear F-actin cell phenotypes, for classifying the entire spectrum of oral epithelial dysplasia and oral squamous cell carcinoma. We enrolled subjects with oral potentially malignant disorders, subjects with previously diagnosed malignant lesions, and healthy volunteers without lesions and obtained brush cytology specimens and matched scalpel biopsies from 486 subjects. Histopathological assessment of the scalpel biopsy specimens classified lesions into 6 categories. Brush cytology specimens were analyzed by machine learning classifiers trained to identify relevant cytological features. Multimodal diagnostic models were developed using cytology results, lesion characteristics, and risk factors. Squamous cells with nuclear F-actin staining were associated with early disease (i.e., lower proportions in benign lesions than in more severe lesions), whereas small round parabasal-like cells and leukocytes were associated with late disease (i.e., higher proportions in severe dysplasia and carcinoma than in less severe lesions). Lesions with the impression of oral lichen planus were unlikely to be either dysplastic or malignant. Cytological features substantially improved upon lesion appearance and risk factors in predicting squamous cell carcinoma. Diagnostic models accurately discriminated early and late disease with AUCs (95% CI) of 0.82 (0.77 to 0.87) and 0.93 (0.88 to 0.97), respectively. The cytological features identified here have the potential to improve screening and surveillance of the entire spectrum of oral potentially malignant disorders in multiple care settings.

3326Infective endocarditis after transcatheter aortic valve implantation: findings from a UK nationwide linkage study

Introduction

Infective endocarditis (IE) is a potentially fatal complication of prosthetic valve replacement and increasing use of transcatheter aortic valve implantation (TAVI) has resulted in a new elderly and frail population at increased risk of IE. The incidence of IE after TAVI and factors that influence the risk and subsequent outcome are relatively unknown.

Purpose

To describe the incidence, predictors, echocardiographic findings, microbiology and clinical outcomes of IE following TAVI in the United Kingdom (UK).

Methods

Patients who underwent TAVI between Jan 1 2007 and Dec 31 2016 were identified from the UK TAVI database held by the National Institute for Cardiovascular Outcomes Research. For this cohort, all hospital admissions with a primary diagnosis of IE were identified by linkage with the NHS Hospital Episode Statistics Admitted Patient Care database, or by contact with regional TAVI centres. Additional information concerning clinical presentation, imaging findings, microbiology, management and patient outcome were obtained where possible from the treating physician.

Results

A total of 16,014 patients underwent TAVI, of whom 157 developed IE over a median follow-up of 23.8 (IQR 7.8–52.4) months - an overall incidence of 0.98% (0.53% at one year post-TAVI). The mean age of patients with IE was 79.2±7.8 years, and 69% were male. The median time to IE following TAVI was 10.0 (IQR 4.0–22.3) months.

On multivariate analysis, IE was significantly more common in men (HR 2.05, 95% CI 1.35–3.11, p=0.001) and in patients receiving mechanically-expandable (HR 2.15, 95% CI 1.16–4.01, p=0.015) or balloon-expandable valves (HR 1.60, 95% CI 1.01–2.52, p=0.045) compared to self-expanding valves. IE was also more common in those with an aortic valve peak gradient following TAVI deployment greater than median (HR 1.81, 95% CI 1.23–2.67, p=0.003).

The most common presenting symptom was fever (present in 67.1%). The most frequent causal organisms were enterococci (25.9%), followed by oral streptococci (16.4%) and Staphylococcus aureus (11.8%). Transoesophageal echocardiography demonstrated vegetations in 72.5% of patients, most commonly on the TAVI valve leaflets (58.8%). Only 8.24% of patients underwent surgical valve intervention.

Survival rates at hospital discharge and one year follow up were 61.4% and 54.4%, respectively. Specific factors associated with one-year mortality were cardiogenic shock (HR 4.6, 95% CI 2.1–10.3, p=0.0002), septic shock (HR 3.4, 95% CI 1.4–8.3, p=0.006) and stroke (HR 4.9, 95% CI 1.46–16.7, p=0.01).

Conclusions

The incidence of IE one year after TAVI was 0.53% and greater risk was associated with male sex, mechanically-expandable and balloon-expandable valves, and elevated post-deployment valve gradient. Enterococci were the most common causative organism. Overall survival at one year was 54.4%, with adverse outcome predicted by cardiogenic shock, septic shock or stroke.

Association of MMP but not TIMP-1 gene polymorphisms with recurrent aphthous stomatitis

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is a common oral inflammatory disease induced by genetic and environmental factors. Gelatinases (MMP-2 and MMP-9) and their natural inhibitor TIMP-1 are active players in the inflammatory process. We aimed to determine whether inheritance of specific MMP-2, MMP-9, or TIMP-1 gene polymorphisms is associated with RAS susceptibility.

SUBJECTS AND METHODS

Ninety-six RAS patients and 153 healthy controls were studied. Five polymorphisms were genotyped: rs17576, rs3918242, and rs11697325 in MMP-9, MMP-2 rs2285053, and TIMP-1 rs6609533. Association was assessed by logistic regression analysis after adjustment for confounding factors. Linkage disequilibrium (LD) was assessed using the Haploview program.

RESULTS

MMP-9 rs11697325 was significantly associated with RAS, with an increase in the AA genotype in patients, determined using χ(2) analysis (OR = 2.3, P = 0.006) and adjusted regression analysis (OR = 3.1, P = 0.009). MMP-9 rs11697325 and rs17576 showed strong LD (D' = 0.95), with an increase in the AA haplotype (P = 0.023) and a decrease in the GA haplotype (P = 0.015) in patients.

CONCLUSIONS

This is the first study to investigate the association of MMPs or TIMP-1 with RAS. We found a significant association between MMP-9 rs11697325 polymorphisms and RAS. Confirmatory studies in other populations and functional investigations are needed to determine the role of these genes in RAS.

NICE guidance on antibiotic prophylaxis to prevent infective endocarditis: a survey of clinicians' attitudes

BACKGROUND

Since the introduction of the National Institute for Health and Clinical Excellence (NICE) guideline (CG064) in 2008 recommending cessation of antibiotic prophylaxis (AP) against infective endocarditis (IE), low level prescribing persists in the UK and is a potential reason why there has been no significant change in the general upward trend in cases of IE.

AIM

To undertake a survey of dentists (Ds), cardiologists and cardiothoracic surgeons (C/CTSs) and infection specialists (ISs) to determine why this might be the case.

DESIGN

Internet questionnaire-based survey.

METHODS

A questionnaire was distributed by email to specialists via UK national societies.

RESULTS

A total of 1168 responses were received. All the specialist groups are aware of the guideline (99%). Ds are broadly satisfied, whereas C/CTSs are not. Most Ds follow the NICE guidance (87%), whereas many C/CTSs (39%) do not; ISs adopt a middle course (56%). Even amongst Ds, a significant proportion believe that patients with a prosthetic heart valve (25%) or previous history of IE (38%) should receive AP. A total of 36% of Ds have prescribed AP since March 2008 and many have undertaken procedures where AP has been prescribed by someone else. The majority of respondents (65%) feel that more evidence is required, preferably in the form of a randomized controlled trial.

CONCLUSION

Many patients perceived to be at high risk of IE are still receiving AP in conflict with current NICE guidance.

Tissue-engineered oral mucosa

Advances in tissue engineering have permitted the three-dimensional (3D) reconstruction of human oral mucosa for various in vivo and in vitro applications. Tissue-engineered oral mucosa have been further optimized in recent years for clinical applications as a suitable graft material for intra-oral and extra-oral repair and treatment of soft-tissue defects. Novel 3D in vitro models of oral diseases such as cancer, Candida, and bacterial invasion have been developed as alternatives to animal models for investigation of disease phenomena, their progression, and treatment, including evaluation of drug delivery systems. The introduction of 3D oral mucosal reconstructs has had a significant impact on the approaches to biocompatibility evaluation of dental materials and oral healthcare products as well as the study of implant-soft tissue interfaces. This review article discusses the recent advances in tissue engineering and applications of tissue-engineered human oral mucosa.

Development, optimization and characterization of a full-thickness tissue engineered human oral mucosal model for biological assessment of dental biomaterials

Restorative dental materials and oral health care products come into direct contact with oral mucosa and can cause adverse reactions. In order to obtain an accurate risk assessment, the in vitro test model must reflect the clinical situation as closely as possible. The aim of this study was to develop and optimize a three-dimensional full-thickness engineered human oral mucosal model, which can be used for biological assessment of dental materials. In this study human oral fibroblasts and keratinocytes were isolated from patients and seeded onto a number of collagen-based and synthetic scaffolds using a variety of cell seeding techniques and grown at the air/liquid interface to construct human oral mucosa equivalents. Suitability of 10 different scaffolds for engineering human oral mucosa was evaluated in terms of biocompatibility, biostability, porosity, and the ability to mimic normal human oral mucosa morphology. Finally an optimized full-thickness engineered human oral mucosa was developed and characterized using transmission electron microscopy and immunostaining. The oral mucosa reconstruct resembled native human oral mucosa and it has the potential to be used as an accurate and reproducible test model in mucotoxicity and biocompatibility evaluation of dental materials.

Tissue-engineered oral mucosa: a review of the scientific literature

Tissue-engineered oral mucosal equivalents have been developed for clinical applications and also for in vitro studies of biocompatibility, mucosal irritation, disease, and other basic oral biology phenomena. This paper reviews different tissue-engineering strategies used for the production of human oral mucosal equivalents, their relative advantages and drawbacks, and their applications. Techniques used for skin tissue engineering that may possibly be used for in vitro reconstruction of human oral mucosa are also discussed.

A systematic review of placebo-controlled randomized clinical trials of treatments used in oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is one of the commoner conditions seen in oral medicine clinics. Current treatments are palliative rather than curative. Numerous treatments have been tried but many have not been evaluated in randomized controlled trials (RCTs).

OBJECTIVES

To review the effectiveness and safety of any therapy compared with placebo for the treatment of symptomatic OLP.

METHODS

A systematic review of 11 RCTs, totalling 223 patients was done. The main outcome measures used were improvement of signs (erythema, reticulation, ulceration) and symptoms (pain, discomfort) usually after 8 weeks of therapy.

RESULTS

Eleven interventions were grouped into four therapeutic classes (topical ciclosporins, topical or systemic retinoids, topical steroids and phototherapy) for comparison. No therapy was replicated exactly. Trials recording the same outcomes in each therapeutic class were pooled. The largest number of pooled trials was four. Small odds ratios with very wide confidence intervals indicating statistically significant but imprecisely known treatment benefits were seen in all but one trial. Only systemic agents were associated with treatment toxicities; all other side-effects were mild and mainly local.

CONCLUSIONS

The results are tempered by the small study sizes, lack of replication, lack of standardized outcome measures and the very high likelihood of publication bias. Therefore this review provides only circumstantial evidence for the superiority of the assessed interventions over placebo for the palliation of symptomatic OLP. There is a need for larger placebo-controlled RCTs with carefully selected and standardized outcome measures.

Polymorphisms in the IL-10 and IL-12 gene cluster and risk of developing recurrent aphthous stomatitis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is a common, painful, ulcerative condition of the mouth. Although there is no clear genetic mode of inheritance, there is evidence that inheritance of specific gene polymorphisms may predispose individuals to RAS. AlsoTh1 cell mediated immune responses under the control of IL-10/IL-12 are thought to play an important role in its pathogenesis.

OBJECTIVE

The objective of this study was to investigate the possibility that susceptibility to RAS is associated with the inheritance of specific gene polymorphisms for the T cell regulatory cytokines interleukin-10 (IL-10) and interleukin-12 (IL-12).

PATIENTS AND METHODS

One hundred RAS patients and 91 ethnically matched controls were genotyped for the IL-10-592, and -1082 polymorphisms, and the IL-12 1188 polymorphism. Chi-square analysis was used to compare the allele frequencies and genotypes of cases and controls.

RESULTS

No significant association was identified between inheritance of specific alleles or genotypes of the IL-10-592 and -1082 polymorphisms or IL-12 1188 polymorphism and susceptibility to RAS.

CONCLUSIONS

We were unable to demonstrate an association between the inheritance of specific IL-10 or IL-12 gene polymorphisms and RAS susceptibility.

Oral mucosal keratinocytes express RANTES and ICAM-1, but not interleukin-8, in oral lichen planus and oral lichenoid reactions induced by amalgam fillings

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa characterized by a band-like accumulation of lymphocytes in the connective tissue adjacent to the basement membrane as well as intraepithelially. Amalgam fillings can induce oral lichenoid reactions (OLR) that are similar to OLP. The adhesion molecule ICAM-1 and the chemokines interleukin-8 and RANTES all play central roles in leucocyte trafficking. The aim of this study was to investigate the possible role of these molecules in the migration of leucocytes into the oral mucosa in OLP and OLR. Standard immunoperoxidase techniques were used to visualize the expression of ICAM-1, RANTES and interleukin-8 in frozen biopsy sections. ICAM-1 was expressed by endothelial cells, but not by keratinocytes, in normal oral mucosa. ICAM-1 was expressed by keratinocytes in 11 of 12 biopsies of OLP and in six of seven biopsies of OLR. In all of these cases ICAM-1 was also expressed by endothelial cells and leucocytes. Although not present in normal oral mucosa, RANTES was expressed by keratinocytes in 21 of 24 biopsies of OLP and in seven of seven cases of OLR. Interleukin-8 was not detected in any of the samples. The expression of ICAM-1 and RANTES by epithelial keratinocytes in the oral mucosa in OLP and OLR could be a key inflammatory mechanism in these diseases.

Recurrent aphthous stomatitis and gene polymorphisms for the inflammatory markers TNF-alpha, TNF-beta and the vitamin D receptor: no association detected

OBJECTIVE

To investigate the possibility that minor recurrent aphthous stomatitis (MiRAS) is associated with the inheritance of specific gene polymorphisms for markers associated with macrophage driven inflammation, i.e. tumor necrosis factor-alpha (TNF-alpha), TNF-beta or the vitamin D receptor (VDR).

SETTING

MiRAS is a common, painful, ulcerative condition of the mouth. Its etiology is unknown although mononuclear inflammatory cells are thought to play an important role. There is no clear genetic mode of inheritance, however, many patients report a positive family history and disease concordance is significantly higher in monozygotic than dizygotic twins, suggesting a polygenic mode of inheritance.

METHODS

Ninety-five MiRAS patients and an ethnically matched control population were genotyped for TNFA-308, TNFB Ncol and VDR (intron 8 and exon 9) polymorphisms. Chi-square analysis was used to compare the allele frequencies and genotypes of cases and controls.

RESULTS

No significant association was identified between inheritance of specific alleles or genotypes of the TNFA-308, TNFB Ncol and VDR (intron 8 and exon 9) polymorphisms and susceptibility to MiRAS.

CONCLUSIONS

Inheritance of specific gene polymorphisms for TNF-alpha, TNF-beta or VDR does not appear to be a significant factor in determining susceptibility to MiRAS.

Adverse reactions associated with the use of eugenol in dentistry

Eugenol is a material commonly used in dentistry with few reported side effects. It is not however, a bio-friendly material when in contact with oral soft tissues. It can produce both local irritative and cytotoxic effects, as well as hypersensitivity reactions. Here we report on two cases of adverse local reaction to eugenol, contained within a temporary restorative material and a temporary cementation material respectively, which illustrate these problems.

IL-1B and IL-6 gene polymorphisms encode significant risk for the development of recurrent aphthous stomatitis (RAS)

Recurrent aphthous stomatitis (RAS) is an, ulcerative condition of the mouth, with a polygenic mode of inheritance in which cytokines are thought to play an important role. Ninety-one RAS patients and 91 controls were genotyped for known IL-1A, IL-1B, IL-1RN and IL-6 gene polymorphisms. Inheritance of the G allele of the IL-1B -511 polymorphism was strongly associated with RAS (OR = 2.5, P < 0.00002), with increased numbers of G/G homozygotes (OR = 4.5, P < 0.0005). The G allele of IL-6 -174 also occurred more frequently in RAS (OR = 2.6, P < 0.0001) with greatest risk associated with G/G homozygosity (OR = 3.4, P < 0.0001). IL-1RN VNTR 1/1 homozygotes also occurred more frequently in RAS (OR = 2.0, P < 0.02). Inheritance of the G/G genotype of both IL-1B and IL-6 was a particularly strong predictor for RAS (OR = 8.5).

Minor recurrent aphthous stomatitis and smoking: an epidemiological study measuring plasma cotinine

OBJECTIVE

To compare blood cotinine levels between a group of patients with minor recurrent aphthous stomatitis (RAS) and a group representative of the general population, matched for age and gender.

SETTING

Although smoking has been implicated as a protective factor in RAS, few studies have compared the prevalence of smoking in RAS patients with population controls. Cotinine is a smoking derivative with a long half-life in the circulation. Measurement of plasma cotinine levels provides an accurate and objective measurement of an individual's cigarette consumption.

METHODS

Blood samples were taken from 84 RAS patients and 81 controls. A microplate enzyme immunoassay (EIA) was used to detect plasma cotinine levels.

RESULTS

The number of RAS patients [2 (2.4%)] who were smokers (plasma cotinine > 25 microg ml(-1) was significantly lower than in the control group [12 (14.8%); P = 0.00102]. Furthermore, the mean cotinine level amongst smokers in the RAS group was significantly lower than in smokers in the control group (P = 0.0068).

CONCLUSION

This study shows that a group of RAS patients is significantly less likely to contain smokers than a matched control population, and among smokers the level of cigarette use was significantly lower in RAS patients than the control population. The perceived negative association between RAS and smoking was supported by this epidemiological study.

Immune mechanisms in oral lichen planus

Although we still don't know the cause, there has been much research into the immune and pathological mechanisms that underlie oral lichen planus (OLP) and it is now possible to piece together a much clearer picture of the disease process. There is consensus that in OLP there is chronic, cell-mediated, immune damage to basal keratinocytes in the oral mucosa that are recognized as being antigenically foreign or altered. In most cases, however, the identity of the target antigen remains unknown. It is likely that cytokines released by the affected keratinocytes, and the associated inflammatory infiltrate, play a key role in the selective recruitment of the T-cell-dominated infiltrate that characterizes OLP, through their ability to induce adhesion molecule expression as well as further cytokine and chemokine release. In susceptible individuals, chronic presentation of antigen by basal keratinocytes may perpetuate the condition and direct cell-mediated immune damage on the keratinocytes.

Activation of oral keratinocytes by mercuric chloride: relevance to dental amalgam-induced oral lichenoid reactions

BACKGROUND

Despite the benefits of mercury-containing amalgam dental fillings there are growing concerns regarding the potential adverse health effects arising from exposure to mercury released from fillings. In some individuals this process may result in a local lichenoid reaction of the oral mucosa.

OBJECTIVES

The aim of this study was to investigate the possibility that mercury salts released from amalgam fillings might act directly on oral keratinocytes to induce changes that could promote the development of such lesions.

METHODS

In vitro experiments were performed in which normal oral and cutaneous keratinocytes were cultured in the presence of mercuric chloride (HgCl2). ICAM-1 expression and the release of cytokines was determined by enzyme-linked immunosorbent assay techniques. T-cell binding to HgCl2-pretreated keratinocytes was assessed using a colorimetric method.

RESULTS

Subcytotoxic concentrations of HgCl2 induced a concentration-related increase in ICAM-1 expression and consequent T-cell binding on oral, but not cutaneous, keratinocytes. HgCl2 also stimulated the release of low levels of tumour necrosis factor-alpha and interleukin-8 (but not RANTES), and inhibited the release of interleukin-1alpha by oral keratinocytes.

CONCLUSIONS

This study provides evidence that oral keratinocytes may play an integral part in initiating the pathogenesis of amalgam-induced lichenoid reactions.

Investigation and medical management of trigeminal neuralgia by consultant oral and maxillofacial surgeons in the British Isles

Trigeminal neuralgia is an extremely painful affliction of the face that is treated by various specialists including oral and maxillofacial surgeons. Some aspects of its management remain controversial, including screening for secondary trigeminal neuralgia, and the monitoring of treatment with carbamazepine. There is, however, little information available about current practice. A postal questionnaire was sent to 254 fellows of the British Association of Oral and Maxillofacial Surgeons (BAOMS) about v arious aspects of the management of trigeminal neuralgia. One hundred and seventy nine replies (70%) were received. Orofacial and cranial nerve examinations were undertaken by the majority of surgeons, but most did not routinely arrange computed tomograp hy or magnetic resonance imaging for all patients, nor did they refer the patient to a neurologist. In contrast with current recommendations, warnings about the adverse effects of carbamazepine were given by only a few surgeons, while most routinely monitored full blood counts.

Violence and aggression at work

The issue of violence and aggression towards healthcare personnel has received increasing attention over recent years. Surveys indicate that such behaviour does occur in both hospital and community dental settings, although in comparison, many other healthcare workers appear to be at greater risk. Information and advice to prevent and manage such situations, should they occur, are available.

Oral and skin keratinocytes are stimulated to secrete monocyte chemoattractant protein-1 by tumour necrosis factor-alpha and interferon-gamma

Monocyte chemoattractant protein-1 (MCP-1) is a member of the CC subfamily of chemokines. It is chemoattractant for monocytes, activated memory T cells and dendritic cells. We studied MCP-1 mRNA and protein production in cultured human oral keratinocytes (OK) and skin keratinocytes (SK). MCP-1 production was undetectable in resting keratinocytes. However, stimulation with tumour necrosis factors (TNF-alpha) or interferon-gamma (IFN-gamma) induced MCP-1 mRNA and protein synthesis in both cell types. Together, TNF-alpha and IFN-gamma acted synergistically to increase MCP-1 production. In each case MCP-1 production was greater for SK than OK. The kinetics of IFN-gamma-induced MCP-1 production were similar for both cell types, peaking around 72 h. In contrast, TNF-alpha induced a more rapid increase in MCP-1 production by SK than OK, peak production occurring after 24 and 72 h, respectively. IL-1alpha and IL-4 did not induce MCP-1 production. However, in combination with IFN-gamma, they induced a small extra increase in MCP-1 production in SK but not OK.

Growth-regulated peptide-alpha (GRO-alpha) production by oral keratinocytes: a comparison with skin keratinocytes

Growth regulated peptide (GRO-alpha) is chemotactic for neutrophils. It also stimulates keratinocyte proliferation and migration, and angiogenesis in cutaneous wound healing. We compared GRO-alpha production by normal human skin and oral keratinocytes, and the effects of cytokine stimulation. Resting keratinocytes produced little, if any, GRO-alpha. TNF-alpha induced a large increase in GRO-alpha mRNA and protein production in both cell types (P<0.001). However, the response of oral keratinocytes was significantly higher (P<0.01). Oral, but not skin, keratinocytes also produced significant amounts of GRO-alpha in response to IL-1 alpha (P<0.005) and IL-4 (P<0.01) stimulation. Indeed, there was an additive effect on GRO-alpha production when oral keratinocytes were stimulated with combinations of TNF-alpha and IL-1 alpha or TNF-alpha and IL-4. Neither cell type responded to interferon gamma. Keratinocyte GRO-alpha production may help selectively recruit neutrophils in mucocutaneous inflammatory diseases, and differences in production by skin and oral keratinocyte could explain the different presentation of these diseases at the two sites. The increased GRO-alpha responsiveness of oral keratinocytes may also help explain the excellent wound healing properties of oral mucosa.

Medical emergencies: the experience of staff of a UK dental teaching hospital

OBJECTIVE

To assess the frequency of faints and other medical emergencies experienced by staff of a UK dental hospital. To investigate the training they had received in the management of medical emergencies, their perception of readiness to deal with emergencies and future training needs.

SUBJECTS

All 193 clinical staff (dentists, hygienists, nurses and radiographers) of the University Dental Hospital of Manchester.

DESIGN

Structured questionnaire with covering letter, reminders sent to non-responders.

RESULTS

There was an 82% response. Fainting was the commonest event: other medical emergency events were experienced with an average frequency of 1.8 events per year, with the highest frequency reported by staff in oral surgery. Most expressed a need for further training: only 3% felt no need.

CONCLUSIONS

Medical emergencies occur in dental hospital practice more frequently but in similar proportions to that found in general dental practice. There is a perceived need for further training among dental hospital staff in the management of medical emergencies.

The effect of sodium lauryl sulphate, triclosan and zinc on the permeability of normal oral mucosa

OBJECTIVE

Sodium lauryl sulphate (SLS), an important component in many oral health products, is well established as a contact irritant in skin. Recent studies have suggested that it may also affect the structural integrity of oral mucosa. SLS is rarely used alone in dentifrices or mouthwashes and the aim of this study was to establish the effect of SLS both alone and in combination with Triclosan (TCN) and zinc (Zn) on the permeability barrier properties of normal human oral mucosa.

METHOD

Ventral tongue mucosa was obtained from nine males and seven females within 60 h of death and stored frozen at -70 degrees C until use. The permeability of the tissue to tritiated water was measured after pretreatment for 15 min with SLS alone, SLS/TCN, SLS/Zn and a SLS/TCN/Zn mixture. Treatment with distilled water (DW) served as control. The histological appearance of the tissue before and after treatment was also examined by light microscopy.

RESULTS

SLS treatment caused a significant increase in water permeability compared to control tissue (Kp = 11.7 +/- 1.00; 4.96 +/- 0.50 respectively; P < 0.005). Treatment with a SLS/TCN/Zn mixture, however, had no effect on the permeability to water (Kp = 5.5 +/- 0.56). Histological examination revealed that tissue exposed to SLS had a marked disruption of the epithelial surface whilst tissue treated with a SLS/TCN/Zn mixture was indistinguishable from controls.

CONCLUSION

Although mucosa exposed to SLS alone showed an increase in permeability to water, the addition of TCN and Zn to SLS appeared to prevent this effect. As SLS is included in some dental products to solubilise compounds such as TCN, its presence may have no effect on the permeability barrier property of oral mucosa.

Delayed and immediate hypersensitivity reactions associated with the use of amalgam

Hypersensitivity to the constituents of dental amalgam is uncommon. When it occurs it typically manifests itself as a lichenoid reaction involving a delayed, type IV, cell-mediated hypersensitivity response. Rarely, a more acute and generalised response can occur involving both the oral mucosa and skin. We describe two cases that illustrate the presentation and management of these two types of reaction.

Mechanisms of binding of cutaneous lymphocyte-associated antigen-positive and alphaebeta7-positive lymphocytes to oral and skin keratinocytes

Intraepithelial lymphocytes (IEL) utilize the integrin alphaebeta7 on their surface to bind to E-cadherin on epithelial cells in the gut and breast. In oral mucosa and skin IEL express alphaebeta7 and the cutaneous lymphocyte-associated antigen (CLA) but the mechanisms of adhesion of these subsets to keratinocytes are unknown. Levels of alphaebeta7 and CLA were up-regulated on peripheral blood lymphocytes (PBL) by transforming growth factor-beta (TGF-beta) and interleukin-12 (IL-12), respectively, and both groups of lymphocytes adhered onto oral and skin keratinocytes. Adhesion of IL-12-activated PBL was totally abolished by anti-lymphocyte-associated function antigen type 1 (anti-LFA-1) antibodies but was unaffected by anti-alphaebeta7 antibodies indicating that adhesion of the CLA-positive subset is mediated via LFA-1 interaction with intercellular adhesion molecule-1 (ICAM-1). Adhesion of TGF-beta-activated PBL to E-cadherin-positive oral and skin keratinocytes was partially inhibited by anti-alphaebeta7 antibodies but was unaffected by the blocking antibody E4.6 against E-cadherin which detects the binding site for alphaebeta7-positive lymphocytes in breast and gut epithelium. TGF-beta-activated PBL also bound to an E-cadherin-negative oral keratinocyte cell line and adhesion was inhibited by anti-alphaebeta7 antibodies. These results strongly suggest that in oral epithelium and epidermis alphaebeta7-positive lymphocytes do not bind to E-cadherin and there may be a novel second ligand for the alphaebeta7 integrin.

Recurrent Kawasaki disease

Kawasaki disease (mucocutaneous lymph node syndrome) is a disease of unknown aetiology characterised by vasculitis which may affect the coronary arteries. Young children are most commonly affected although the disease has been described in adults. We report a case of recurrent Kawasaki disease which presented to an oral medicine clinic, where early recognition prompted appropriate management.

Induction of adhesion molecule expression on blood vessels and keratinocytes in recurrent oral ulceration

Adhesion molecules are known to play a crucial role in the recruitment of inflammatory cells to sites of inflammation. In this study endothelial cell and keratinocyte adhesion molecule expression in recurrent oral ulcers (ROU) (n = 13) was compared with that found in normal oral mucosa (NOM) (n = 11) and experimentally induced ulcers (EIU) (n = 5) by using immunohistochemistry. Significantly greater expression of both vascular cell adhesion molecule- (VCAM-1) and E-selectin was demonstrated on vasculature in ROU compared with that found in both NOM and EIU. Induction of keratinocyte intercellular adhesion molecule-1 (ICAM-1) was also a prominent feature of ROU. The expression of VCAM-1 and E-selectin on blood vessels in ROU is likely to be important in the accumulation of lymphocytes that characterise early aphthous lesions. The induction of keratinocyte ICAM-1 may facilitate lymphocyte invasion of the epithelium in ROU, which may ultimately result in ulcer formation.

The effect of a sodium lauryl sulfate-free dentifrice on patients with recurrent oral ulceration

OBJECTIVE

Sodium lauryl sulphate (SLS) is the most commonly used detergent in dentifrices. Recent reports have suggested that it may exacerbate conditions with compromised epithelial integrity. The aim of this study was to compare the effect of an SLS-free dentifrice and an SLS-containing dentifrice on recurrent oral ulceration (ROU).

DESIGN

A double-blind crossover clinical trial was carried out during which subjects used an SLS dentifrice for 8 weeks and an SLS-free dentifrice for 8 weeks. Each phase was preceded by a 2-week washout period.

SETTING

A UK dental teaching hospital.

SUBJECTS AND METHODS

Forty-seven subjects completed the trial. They were all in the age range 10-62 years, had regularly recurrent oral ulceration reporting at least one to two ulcers per month and had normal levels of vitamin B12, ferritin and folate.

MAIN OUTCOME MEASURES

The trial phases were compared for the following ulcer parameters--number of ulcer days, total pain scores, number of ulcer episodes, and number of ulcers. Additional parameters compared were the number of ulcers per episode, ulcer duration, total pain per episode and ulcer size.

RESULTS

None of the ulcer parameters measured was significantly affected by the use of the SLS-free dentifrice as compared with the SLS dentifrice.

CONCLUSION

SLS-free dentifrice had no significant effect on ulcer pattern in the ROU study group.

Intra-epithelial subpopulations of T lymphocytes and Langerhans cells in oral lichen planus

This study has addressed the question of whether there is selective recruitment and distribution of intra-epithelial leucocytes in lesions of oral lichen planus (OLP). T-lymphocyte subsets were examined in the epithelium and peripheral blood of patients and controls using flow cytometry and double immunofluorescence, and the relationship between keratinocyte intercellular adhesion molecule-1 (ICAM-1) expression with T-lymphocyte and Langerhans cell (LC) distribution was examined. The circulating 'memory' subset (CD45RO+) of T-helper cells (CD4+) was increased from 49.1% in controls to 65.7% in patients (P=0.005), while the 'naive' subset (CD45RA+), which was absent from control epithelium, comprised 24% of helper cells in OLP (P=0.016). Fewer LC expressed CD45RO in OLP than in controls (P=0.037) and all T-cell and LC counts were significantly raised in ICAM-1-expressing areas of epithelium. These data demonstrate changes in intra-epithelial T-lymphocyte and LC populations compared with normal oral mucosa and suggest there is selective recruitment in OLP. In addition, keratinocyte ICAM-1 expression does appear to be associated with accumulation of infiltrating T lymphocytes and LC.

Derangement of warfarin anticoagulation by miconazole oral gel

The potentiation of the anticoagulant effects of warfarin by miconazole, when used in oral gel form, is described in three patients. The associated morbidity is examined, emphasising the importance of considering this potentially serious interaction when prescribing antifungal agents to patients on oral anticoagulants.

Cutaneous lymphocyte associated antigen (CLA) and alpha e beta 7 integrins are expressed by mononuclear cells in skin and oral lichen planus

The cutaneous lymphocyte associated- (CLA-) positive subset of lymphocytes appears to migrate preferentially into skin by interacting with E-selectin on vascular endothelium; lymphocytes expressing the alpha e beta 7 integrin accumulate preferentially in the epithelium of the gastrointestinal tract. To determine whether the mononuclear cell population of the oral mucosa resembles that of the skin or intestine, and using lichen planus as a model, the proportions of CLA- and alpha e beta 7-positive cells in the epithelium, lamina propria and peripheral blood were compared by immunostaining and flow cytometry. In both skin and oral lichen planus, selective accumulation of CLA-positive cells was seen in the epithelium but not in the lamina propria. In contrast, large numbers of alpha e beta 7-positive intraepithelial cells were found in oral but not in skin lichen planus. These results show that in terms of CLA and alpha e beta 7 expression there are important differences in the mononuclear cell population of oral mucosa and skin.

Chemokines and chemokine receptors: the key to understanding AIDS

This article reviews the recent rapid developments in research that have demonstrated the importance of chemokines and their receptors in HIV infection and the progression to AIDS. These discoveries have transformed our understanding of how the virus may infect cells and why certain individuals may be resistant to HIV infection, and for the first time have opened up the very real prospect of developing strategies to prevent and treat this disease.

Raised levels of circulating VCAM-1 and circulating E-selectin in patients with recurrent oral ulceration

Endothelial cell (EC) adhesion molecules VCAM-1 (vascular cell adhesion molecule-1), E-selectin and ICAM-1 (intercellular adhesion molecule-1) are essential for the binding of inflammatory cells to ECs. Recently, circulating forms of these molecules have been detected in a number of vasculitic disease processes. Recurrent oral ulceration (ROU) has some features of a vasculitic disease process. The purpose of this study was, therefore, to compare cVCAM-1, cE-selectin and cICAM-1 levels in 50 patients with ROU and 50 age- and sex-matched controls. Levels of circulating adhesion molecules were quantified using specific "sandwich" ELISA assays. The cVCAM-1 and cE-selectin levels were significantly raised in ROU patients (P < 0.00005 and P < 0.05, respectively) but there was no significant increase in cICAM-1 levels. These findings may result from endothelial cell activation or damage at the ulcer site.

Raised anti-endothelial cell autoantibodies (AECA), but not anti-neutrophil cytoplasmic autoantibodies (ANCA), in recurrent oral ulceration: modulation of AECA binding by tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma)

Recurrent oral ulceration (ROU) is a common oral mucosal condition of unknown etiology. However, there is evidence to suggest that vasculitis may play a role. Here we investigate the presence in ROU of two autoantibodies associated with vasculitis, AECA and ANCA. AECA target as yet unidentified antigens on the endothelial cell surface and have been identified in patients with vasculitic disorders and inflammatory conditions with a vasculitic component. ANCA target specific neutrophil-associated proteins and are detected in specific vasculitic and chronic inflammatory disorders. AECA and ANCA levels were studied in 20 ROU patients and 20 controls. IgG AECA to the endothelial cell line ECV 304 were detected in 19 ROU patients and four controls. Levels were significantly raised in ROU both to ECV 304 (P < 0.000 05) and to human umbilical vein endothelial cells (HUVEC) (P < 0.005). Although levels were highest during episodes of ulceration, they were also raised between episodes. Stimulation of endothelial cells with TNF-alpha significantly increased AECA binding of both ROU (P < 0.005) and control samples (P < 0.0001), while IFN-gamma decreased binding (ROU P < 0.0001; controls P < 0.05). In contrast, ANCA were detected in only one patient and none of the controls. The presence of raised levels of AECA lends support to the hypothesis that a vasculitic process may underlie ROU. Moreover, these findings suggest that endothelial cell expression of AECA target antigens is increased by TNF-alpha and decreased by IFN-gamma stimulation.

T cell antigen receptor expression by intra-epithelial lymphocytes in oral lichen planus

The distribution of T lymphocytes expressing the alpha beta or gamma delta heterodimer of the T cell receptor (TCR) was examined in normal oral mucosa (NOM) and reticular oral lichen planus (OLP) using a panel of antibodies specific for CD3, the alpha beta TCR and the gamma delta TCR. Intra-epithelial lymphocytes were counted and epithelial surface length was measured by image analysis. T cells in the lamina propria were not quantified. Total intra-epithelial lymphocytes were increased in OLP compared with NOM (P = 0.0004). The proportions of cells expressing the gamma delta TCR in NOM and OLP were 10% and 9.3%, respectively, suggesting there is no selective recruitment from the circulation of either alpha beta or gamma delta TCR-bearing cells into normal oral epithelium or that affected by OLP. The role, if any, of gamma delta T cells in the pathogenesis of OLP remains to be determined.

Dental attendance patterns in renal transplant recipients

OBJECTIVES

Renal transplant recipients (RTR) represent a large and growing population of individuals on potent immunosuppressant therapy who are at significantly greater risk of developing lip and oral mucosal disease, including lip cancer. The aims of this study were to determine the proportion of RTR receiving regular dental treatment, the dental services they used, and the relationship between the prevalence of lip and intraoral lesions and dental attendance.

DESIGN

The lip and oral mucosa of 159 RTR and 160 controls were examined. Subjects were asked questions about frequency of dental attendance and which service they used.

RESULTS

57.9% RTR attended a dentist regularly compared with 51.3% controls. Among the RTR who attended a dentist regularly, 54.3% visited their general dental practitioner, and 45.6% attended a dental hospital for treatment. This was significantly different from controls where 92.7% of regular attenders used their general dental practitioner (P < 0.001). Although the prevalence of oral lesions in RTR (54.7%) was more than twice as many as controls (19.4%), no significant difference was observed between RTR regular dental attenders and non-attenders.

CONCLUSIONS

This study indicates a clear need for oral health care and screening to be focused on RTR.

Cytokine regulation of major histocompatibility complex antigen expression by human oral and skin keratinocytes

The expression, and cytokine modulation, of major histocompatibility complex (MHC) class I and class II molecules on oral and skin keratinocytes were compared in cell culture. Both cell types expressed class I, but not class II, constitutively. However, stimulation with interferon-gamma, but not interleukin-1 alpha, and -1 beta, tumour necrosis factor-alpha or lymphotoxin, induced increased expression of class I and de-novo expression of HLA-DR on both cell types. Oral keratinocytes differed from skin keratinocytes in that they exhibited greater sensitivity to interferon-gamma stimulation and higher stimulated expression of both class I and HLA-DR. In addition, interferon-gamma stimulated oral, but not skin, keratinocytes to express HLA-DP and -DQ. These observations suggest that, like skin keratinocytes, under certain conditions, oral keratinocytes may be able to act as antigen-presenting cells. This may be important in the initiation and progression of some immune-mediated mucocutaneous diseases. Moreover, differences in MHC expression may help to explain differences in the presentation of these diseases on the skin and oral mucosa.

Masticatory muscle symptoms in a patient with McArdle's disease

Myofascial pain dysfunction syndrome is a syndrome characterized by chronic preauricular pain and tenderness involving the muscles of mastication. The cause is often multifaceted and generally poorly defined. A case of McArdle's disease is discussed in which the patient presented with symptoms consistent with myofascial pain dysfunction syndrome. McArdle's disease is a rare autosomal recessive glycogen storage disorder in which there is a metabolic myopathy that results in exercise intolerance, muscle pain, and tenderness, and that in this patient gave rise to chronic symptoms of myofascial pain. Although uncommon, McArdle's disease should be considered in the diagnosis of patients with symptoms of myofascial pain dysfunction syndrome because the condition has important implications with respect to the patients renal function and because it can be readily distinguished by simple investigations.

Epidermal and oral keratinocytes are induced to produce RANTES and IL-8 by cytokine stimulation

RANTES, interleukin-8 (IL-8), and macrophage inflammatory protein-1-alpha (MIP-1 alpha) exhibit different and highly selective chemotactic activity for leukocytes. Resting cultured normal oral and skin keratinocytes produced little if any of these chemokines. Stimulation with 250-1,000 U/ml of tumor necrosis factor-alpha (TNF-alpha) or interferon-gamma (IFN-gamma) induced both cell types to produce RANTES. Protein levels peaked after 48 h and mRNA levels peaked after 8 h of stimulation. Used combination, TNF-alpha, and IFN-gamma synergistically increased mRNA and protein levels. Amounts of 100-1,000 U/ml of TNF-alpha also induced IL-8 production with peak mRNA levels after 4-24 h of stimulation and maximal protein production after 72 h or more. IL-8 production by oral keratinocytes was significantly greater than that by skin keratinocytes. Although IFN-gamma alone did not induce IL-8 production, it enhanced the effect of TNF-alpha on both cell types. Stimulation for 24 h with 100-1,000 U/ml of IL-alpha also induced IL-8 production by oral but not skin keratinocytes. No MIP-1 alpha production was detected under the conditions investigated. Keratinocyte production of RANTES and IL-8, under the influence of cytokines such as TNF-alpha or IFN-gamma, provides a mechanism for the selective accumulation of leukocytes into immunoinflammatory diseases of the skin and oral mucosa. Differences in their production may help to explain differences in the presentation of these diseases on the skin and oral mucosa.

IL-1 alpha and IL-6 production by oral and skin keratinocytes: similarities and differences in response to cytokine treatment in vitro

IL-1 alpha and IL-6 are important pro-inflammatory and immunomodulatory cytokines and their production by oral (OK) and skin keratinocytes (SK) was compared. OK and SK produced IL-1 alpha, but not IL-6, constitutively. TNF alpha stimulation increased IL-1 alpha production by both cell types and exhibited synergy with interferon gamma (IFN gamma), although the latter had no effect by itself. In contrast, both cell types produced IL-6 in response to TNF alpha, IFN gamma or IL-4, and IFN gamma and IL-4 exhibited synergy with TNF alpha. For all cytokines the levels of IL-6 production were greater for OK than SK and OK, but not SK, produced IL-6 in response to IL-1 alpha stimulation. In addition, the IL-6 response to IL-4 stimulation was more rapid for OK than SK. These observations may explain the similarities and differences in wound healing and immuno-inflammatory diseases affecting the skin and oral mucosa.

Heterogeneity of ICAM-1 expression, and cytokine regulation of ICAM-1 expression, in skin and oral keratinocytes

Differences in expression of intercellular adhesion molecule-1 (ICAM-1) and ICAM-1 mRNA levels were studied in cultured skin and oral keratinocytes before and after stimulation with different pro-inflammatory cytokines. Basal expression of ICAM-1 was undetectable on skin keratinocytes but oral keratinocytes expressed ICAM-1 at high levels. Interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) increased ICAM-1 expression on both cell types, although TNF-alpha had a greater effect on oral than skin keratinocytes (P<0.05) and IFN-gamma was more effective than TNF-alpha on both cell types (P<0.01). In combination, TNF-alpha and IFN-gamma synergistically increased ICAM-1 expression on skin keratinocytes only, although ICAM-1 mRNA was synergistically increased in both cell types. IL-1alpha and IL-1beta induced a small increase in ICAM-1 expression on oral keratinocytes but had no effect on skin keratinocytes.

Dental prescribing: minimising the cost to the patient and the NHS

The high cost of prescription charges, changes in drug availability and the increase in private and independent dental practice means that NHS prescriptions may not be the cheapest or most appropriate way of providing drugs to patients. This article examines this complex area and provides some practical advice.

Oral psoriasis

We present a patient with oral lesions consistent with a diagnosis of oral psoriasis and discuss the relationship of oral and skin lesions in psoriasis.