Wear of human teeth: a tribological perspective

The four main types of wear in teeth are attrition (enamel-on-enamel contact), abrasion (wear due to abrasive particles in food or toothpaste), abfraction (cracking in enamel and subsequent material loss), and erosion (chemical decomposition of the tooth). They occur as a result of a number of mechanisms including thegosis (sliding of teeth into their lateral position), bruxism (tooth grinding), mastication (chewing), toothbrushing, tooth flexure, and chemical effects. In this paper the current understanding of wear of enamel and dentine in teeth is reviewed in terms of these mechanisms and the major influencing factors are examined. In vitro tooth wear simulation and in vivo wear measurement and ranking are also discussed

Practice nurse-supported weight self-management delivered within the national child immunisation programme for postnatal women:a feasibility cluster RCT

Background: Pregnancy is a high-risk time for excessive weight gain. The rising prevalence of obesity in women, combined with excess weight gain during pregnancy, means that there are more women with obesity in the postnatal period. This can have adverse health consequences for women in later life and increases the health risks during subsequent pregnancies. Objective: The primary aim was to produce evidence of whether or not a Phase III trial of a brief weight management intervention, in which postnatal women are encouraged by practice nurses as part of the national child immunisation programme to self-monitor their weight and use an online weight management programme, is feasible and acceptable. Design: The research involved a cluster randomised controlled feasibility trial and two semistructured interview studies with intervention participants and practice nurses who delivered the intervention. Trial data were collected at baseline and 3 months later. The interview studies took place after trial follow-up. Setting: The trial took place in Birmingham, UK. Participants: Twenty-eight postnatal women who were overweight/obese were recruited via Birmingham Women’s Hospital or general practices. Nine intervention participants and seven nurses were interviewed. Interventions: The intervention was delivered in the context of the national child immunisation programme. The intervention group were offered brief support that encouraged self-management of weight when they attended their practice to have their child immunised at 2, 3 and 4 months of age. The intervention involved the provision of motivation and support by nurses to encourage participants to make healthier lifestyle choices through self-monitoring of weight and signposting to an online weight management programme. The role of the nurse was to provide regular external accountability for weight loss. Women were asked to weigh themselves weekly and record this on a record card in their child’s health record (‘red book’) or using the online programme. The behavioural goal was for women to lose 0.5-1 kg per week. The usual-care group received a healthy lifestyle leaflet. Main outcome measures: The primary outcome was the feasibility of a Phase III trial to test the effectiveness of the intervention, as assessed against three traffic-light stop-go criteria (recruitment, adherence to regular self-weighing and registration with an online weight management programme). Results: The traffic-light criteria results were red for recruitment (28/80, 35% of target), amber for registration with the online weight loss programme (9/16, 56%) and green for adherence to weekly self-weighing (10/16, 63%). Nurses delivered the intervention with high fidelity. In the qualitative studies, participants indicated that the intervention was acceptable to them and they welcomed receiving support to lose weight at their child immunisation appointments. Although nurses raised some caveats to implementation, they felt that the intervention was easy to deliver and that it would motivate postnatal women to lose weight. Limitations: Fewer participants were recruited than planned. Conclusions: Although women and practice nurses responded well to the intervention and adherence to self-weighing was high, recruitment was challenging and there is scope to improve engagement with the intervention.Future work: Future research should focus on investigating other methods of recruitment and, thereafter, testing the effectiveness of the intervention.Trial registration: Current Controlled Trials ISRCTN12209332.Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 49. See the NIHR Journals Library website for further project information.</p

Gluten sensitivity enteropathy in patients with recurrent aphthous stomatitis

<p>Abstract</p> <p>Background</p> <p>Gluten sensitive enteropathy (GSE) is an autoimmune enteropathy triggered by the ingestion of gluten-containing grains in susceptible individuals. Recurrent aphthous stomatitis (RAS) may be the sole manifestation of GSE. The aim of this study was to determine the prevalence of gluten sensitivity enteropathy (GSE) in a large group of patients with RAS and assess the efficacy of gluten free diet (GFD) on the improvement of aphthous lesions in those who were diagnosed with GSE.</p> <p>Methods</p> <p>Two hundred and forty seven patients with RAS were included. The patients had at least three aphthous attacks per year. Patients were screened by IgA anti-endomysial antibody (EMA), IgA anti tissue transglutaminase (TTG) and serum IgA level. Those with a positive serology underwent endoscopic biopsies of the duodenal mucosa and patients with negative serology were excluded. The diagnosis of GSE was based on a positive serological test and abnormal duodenal histology. For patients with GSE, gluten free diet was recommended.</p> <p>Results</p> <p>Six out of 247 RAS patients had positive TTG test alone, and one had positive EMA and TTG. All 7 patients with positive serologic tests underwent duodenal biopsies. Histological findings were compatible with GSE in all of them (Marsh I in four patients, Marsh II in two patients and Marsh IIIB in one another.). The mean age of GSE patients was 27.42 ± 10.56 (range, 13 to 40) years old. They were suffering from RAS for an average duration of 4.5 years. All of the 7 GSE patients had not responded to the routine anti-aphthae medications, including topical corticosteroids, tetracycline and colchicine. Four patients who adhered to a strict gluten-free diet showed noticeable improvement in their aphthous lesions over a period of 6 months.</p> <p>Conclusion</p> <p>A significant minority (e.g. 2.83%) of RAS patients have GSE. This could be compared with the 0.9% prevalence of GSE in the general population of Iran. This study suggests that evaluation for celiac disease is appropriate in patients with RAS. Additionally, the unresponsiveness to conventional anti-aphthae treatment could be an additional risk indicator.</p

Tylosis with oesophageal cancer: Diagnosis, management and molecular mechanisms

Research on iRHOM2 in the Kelsell group is funded by an MRC project grant, a MRC Clinical Fellowship (to TM) and a Cancer Research UK program grant

Cytoglobin is upregulated by tumour hypoxia and silenced by promoter hypermethylation in head and neck cancer

Background: Cytoglobin (Cygb) was first described in 2002 as an intracellular globin of unknown function. We have previously shown the downregulation of cytoglobin as a key event in a familial cancer syndrome of the upper aerodigestive tract. Methods: Cytoglobin expression and promoter methylation were investigated in sporadic head and neck squamous cell carcinoma (HNSCC) using a cross-section of clinical samples. Additionally, the putative mechanisms of Cygb expression in cancer were explored by subjecting HNSCC cell lines to hypoxic culture conditions and 5-aza-2-deoxycitidine treatment. Results: In clinically derived HNSCC samples, CYGB mRNA expression showed a striking correlation with tumour hypoxia (measured by HIF1A mRNA expression P=0.013) and consistent associations with histopathological measures of tumour aggression. CYGB expression also showed a marked negative correlation with promoter methylation (P=0.018). In the HNSCC cell lines cultured under hypoxic conditions, a trend of increasing expression of both CYGB and HIF1A with progressive hypoxia was observed. Treatment with 5-aza-2-deoxycitidine dramatically increased CYGB expression in those cell lines with greater baseline promoter methylation. Conclusion: We conclude that the CYGB gene is regulated by both promoter methylation and tumour hypoxia in HNSCC and that increased expression of this gene correlates with clincopathological measures of a tumour's biological aggression.</p

A perspective on the measurement of time in plant disease epidemiology

The growth and development of plant pathogens and their hosts generally respond strongly to the temperature of their environment. However, most studies of plant pathology record pathogen/host measurements against physical time (e.g. hours or days) rather than thermal time (e.g. degree-days or degree-hours). This confounds the comparison of epidemiological measurements across experiments and limits the value of the scientific literature

Comparison of 1- and 2-year screening intervals for women undergoing screening mammography

We compared the long-term impact of 1- and 2-year screening mammography intervals using prognostic, screening, and outcome information for women aged 50–74 years obtained from the Screening Mammography Program of British Columbia in two time periods, prior to 1997 (policy of annual mammography) and after 1997 (biennial mammography). Survival was estimated for both periods using a prognostic model and the expected rate of interval and screen-detected cancers. The likelihood of a screen-detected cancer with annual screening was 2.32 per thousand screens and with biennial screening was 3.32 per thousand screens. The prognostic profile of screen-detected cancers was better than that of interval cancers. Among both screen-detected and interval cancers, the prognostic profiles with annual and biennial screening were similar. The estimated breast cancer-specific survival rates for women undergoing annual and biennial screening mammography were 95.2 and 94.6% at 5 years, and 90.4 and 89.2% at 10 years, respectively. Annual compared to biennial mammography was associated with a 1.2% increase in the estimated 10-year breast cancer-specific survival for women aged 50–74 years, diagnosed with invasive breast cancer after screening programme attendance