Emergency department presentations with suicide and self-harm ideation: a missed opportunity for intervention?

AIMS

Suicidal ideation constitutes a central element of most theories of suicide and is the defining facet separating suicide from other causes of death such as accidents. However, despite a high worldwide prevalence, most research has focused on suicidal behaviours, such as completed suicide and suicide attempts, while the greater proportion who experienced ideation, which frequently precedes suicidal behaviour, have received much less attention. This study aims to examine the characteristics of those presenting to EDs with suicidal ideation and quantify the associated risk of suicide and other causes of death.

METHODS

Retrospective cohort study was performed based on population-wide health administration data linked to data from the Northern Ireland Registry of Self-Harm and centrally held mortality records from April 2012 to December 2019. Mortality data, coded as suicide, all-external causes and all-cause mortality were analysed using Cox proportional hazards. Additional cause-specific analyses included accidental deaths, deaths from natural causes and drug and alcohol-related causes.

RESULTS

There were 1,662,118 individuals aged over 10 years, of whom 15,267 presented to the ED with ideation during the study period. Individuals with ideation had a 10-fold increased risk of death from suicide (hazard ratio [HR_adj] = 10.84, 95% confidence interval [CI] 9.18, 12.80) and from all-external causes (HR_adj = 10.65, 95% CI 9.66, 11.74) and a threefold risk of death from all-causes (HR_adj = 3.01, 95% CI 2.84, 3.20). Further cause-specific analyses indicated that risk of accidental death (HR_adj = 8.24, 95% CI 6.29, 10.81), drug-related (HR_adj = 15.17, 95% CI 11.36, 20.26) and alcohol-related (HR_adj = 10.57, 95% CI 9.07, 12.31) has also significantly increased. There were few socio-demographic and economic characteristics that would identify which of these patients are most at risk of suicide or other causes of death.

CONCLUSIONS

Identifying people with suicidal ideation is recognized to be both important but difficult in practice; this study shows that presentations to EDs with self-harm or suicide ideation represent an important potential intervention point for this hard-to-reach vulnerable population. However, and unlike individuals presenting with self-harm, clinical guidelines for the management and recommended best practice and care of these individuals are lacking. Whilst suicide prevention may be the primary focus of interventions aimed at those experiencing self-harm and suicide ideation, death from other preventable causes, especially substance misuse, should also be a cause of concern.

Effect of Physical Exercise and Genetic Background on Glucose Homeostasis and Liver/Muscle Proteomes in Mice

We compared the parameters related to glucose homeostasis, and liver and muscle proteomes in fluorosis-susceptible (A/J; S) and fluorosis-resistant (129P3/J; R) mice in response to fluoride (F) exposure and exercise. Ninety male mice (45 R-mice and 45 S-mice) were randomized into three groups: (SI; RI) No-F, No-Exercise, (SII; RII) 50 ppm F, No-Exercise, (SIII; RIII) 50 ppm F, Exercise. Overall, mean F concentrations in the plasma and femur were significantly higher in R-mice compared with S-mice. In R-mice, exercise resulted in an increase in F accumulation in the femur. In S-mice, the mean plasma glucose level was significantly higher in Group II compared with Groups I and III. There was an increase in liver proteins involved in energy flux and antioxidant enzymes in non-exercise groups (I, II) of S-mice in comparison with the corresponding groups of R-mice. The results also showed a decrease in muscle protein expression in Group I S-mice compared with their R-mice counterparts. In conclusion, the findings suggest an increased state of oxidative stress in fluorosis-susceptible mice that might be exacerbated by the treatment with F. In addition, fluorosis-susceptible mice have plasma glucose levels higher than fluorosis-resistant mice on exposure to F, and this is not affected by exercise.

Fractional urinary fluoride excretion and nail fluoride concentrations in normal, wasted and stunted 4-5 year-old children in Nepal

INTRODUCTION

It has been suggested that undernourished children are more likely to develop dental fluorosis. We investigated the effects of nutritional status on systemic fluoride metabolism including the proportion of ingested fluoride excreted through urine (i.e. fractional urinary fluoride excretion - FUFE) and fluoride concentration in nail clippings in children, aged 4-5 years, in Nepal.

METHODS

Nutritional status was evaluated using weight-for-age (wasting) and height-for-age (stunting) indices. Total daily fluoride intake (TDFI) was estimated from diet and toothpaste ingestion and 24 -h urine collected to assess daily urinary fluoride excretion (DUFE). FUFE was calculated by dividing DUFE by TDFI. Nail clippings (finger and toe) were collected and analysed for fluoride concentration.

RESULTS

Of the 100 children who participated, 89 provided information to assess FUFE and 51 children provided nail samples. Overall, 86.5 % of the 89 children were wasted and 39.3 % were stunted. When the samples were pooled into binary (affected and non-affected) categories, mean TDFI and mean DUFE were statistically significantly higher in the 77 wasted children (57.7 and 29.7 μg/kgbw/d, respectively) than the 12 non-wasted children (39.4 and 17.0 μg/kgbw/d, respectively). TDFI and DUFE were also statistically significantly higher in the 35 stunted children (65.1 and 34.5 μg/kgbw/d, respectively) than in the 54 non-stunted children (48.8 and 23.7 μg/kgbw/d, respectively). However, mean FUFE was similar in all groups. There were no statistically significant differences in fluoride concentration of either fingernails or toenails among the different categories of wasting, while mean fingernail fluoride concentration was statistically significantly higher in stunted (5.4 μg/g) than in non-stunted children (3.5 μg/g).

CONCLUSION

Our study found no significant effect of nutritional status on the proportion of ingested fluoride excreted in urine (and consequently the proportion retained in the body). These findings suggest that nutritional status may be less likely to be a main risk factor for the development of dental fluorosis than children's dietary habits or total fluoride intake.

Real-time MR tracking of AAV gene therapy with βgal-responsive MR probe in a murine model of GM1-gangliosidosis

Transformative results of adeno-associated virus (AAV) gene therapy in patients with spinal muscular atrophy and Leber's congenital amaurosis led to approval of the first two AAV products in the United States to treat these diseases. These extraordinary results led to a dramatic increase in the number and type of AAV gene-therapy programs. However, the field lacks non-invasive means to assess levels and duration of therapeutic protein function in patients. Here, we describe a new magnetic resonance imaging (MRI) technology for real-time reporting of gene-therapy products in the living animal in the form of an MRI probe that is activated in the presence of therapeutic protein expression. For the first time, we show reliable tracking of enzyme expression after a now in-human clinical trial AAV gene therapy (ClinicalTrials.gov: NTC03952637) encoding lysosomal acid beta-galactosidase (βgal) using a self-immolative βgal-responsive MRI probe. MRI enhancement in AAV-treated enzyme-deficient mice (GLB-1^-/-) correlates with βgal activity in central nervous system and peripheral organs after intracranial or intravenous AAV gene therapy, respectively. With >1,800 gene therapies in phase I/II clinical trials (ClinicalTrials.gov), development of a non-invasive method to track gene expression over time in patients is crucial to the future of the gene-therapy field.

Pharmacokinetics of fluoride in human adults: The effect of exercise

The literature is sparse in terms of the effect of exercise on the pharmacokinetics of fluoride (F) in humans. In a 4-treatment repeated measures cross-over study, we investigated F pharmacokinetics following no exercise (control) and three exercise intensity conditions (light, moderate and vigorous) in healthy adults. At a pre-experimental session, 8 participants (18-30y) residing in a non-fluoridated-area, underwent a VO_{2 max} test to guide the three exercise intensities for the experimental sessions. Participants were on a F-free regime one week before and throughout the four experimental weeks. We measured urinary F excretion (UFE), maximum plasma concentration (Cmax), lag time of Cmax (Tmax), and Area Under the Curve (AUC) for plasma F concentration against time, following F ingestion then no, light, moderate and vigorous exercise. Results showed no statistically significant difference in Tmax among all sessions; whereas Cmax for moderate exercise (226.2 ng/ml) was significantly higher than for no (27.0 ng/ml; p < 0.001), light (105.6 ng/ml; p = 0.016) and vigorous (94.2 ng/ml; p = 0.008) exercise. Mean AUC over 0-90 min following F ingestion was also significantly higher in moderate exercise than for no (p < 0.001), light (p = 0.004) and vigorous (p = 0.001) exercise. Mean UFE over 0-14h was 638.8, 718.7, 574.6 and 450.5  μg for no, light, moderate and vigorous exercise, with no statistically significant differences among different sessions. In conclusion, this human experimental study suggests that moderate exercise may increase the fraction of F absorbed systemically which is therefore available to produce a biological effect. Future studies should be conducted with larger samples, different age groups and using different F doses.

Children and parents' perspectives on the acceptability of three management strategies for dental caries in primary teeth within the 'Filling Children's Teeth: Indicated or Not' (FiCTION) randomised controlled trial - a qualitative study

Background

The Filling Children’s Teeth: Indicated Or Not? (FiCTION) randomised controlled trial (RCT) aimed to explore the clinical- and cost-effectiveness of managing dental caries in children’s primary teeth. The trial compared three management strategies: conventional caries management with best practice prevention (C + P), biological management with best practice prevention (B + P) and best practice prevention alone (PA)-based approaches. Recently, the concept of treatment acceptability has gained attention and attempts have been made to provide a conceptual definition, however this has mainly focused on adults. Recognising the importance of evaluating the acceptability of interventions in addition to their effectiveness, particularly for multi-component complex interventions, the trial design included a qualitative component. The aim of this component was to explore the acceptability of the three strategies from the perspectives of the child participants and their parents.

Methods

Qualitative exploration, based on the concept of acceptability. Participants were children already taking part in the FiCTION trial and their parents. Children were identified through purposive maximum variation sampling. The sample included children from the three management strategy arms who had been treated and followed up; median (IQR) follow-up was at 33.8 (23.8, 36.7) months. Semi-structured interviews with thirteen child-parent dyads. Interviews were transcribed verbatim and analysed using a framework approach.

Results

Data saturation was reached after thirteen interviews. Each child-parent dyad took part in one interview together. The participants were eight girls and five boys aged 5–11 years and their parents. The children’s distribution across the trial arms was: C + P n = 4; B + P n = 5; PA n = 4. Three key factors influenced the acceptability of caries management in primary teeth to children and parents: i) experiences of specific procedures within management strategies; ii) experiences of anticipatory dental anxiety and; iii) perceptions of effectiveness (particularly whether pain was reduced). These factors were underpinned by a fourth key factor: the notion of trust in the dental professionals – this was pervasive across all arms.

Conclusions

Overall children and parents found each of the three strategies for the management of dental caries in primary teeth acceptable, with trust in the dental professional playing an important role.

Dental professionals' experiences of managing children with carious lesions in their primary teeth - a qualitative study within the FiCTION randomised controlled trial

Background

The lack of evidence for the effective management of carious lesions in children’s primary teeth has caused uncertainty for the dental profession and patients. Possible approaches include conventional and biological management alongside best practice prevention, and best practice prevention alone. The FiCTION trial assessed the effectiveness of these options, and included a qualitative study exploring dental professionals’ (DPs) experiences of delivering the different treatment arms. This paper reports on how DPs managed children with carious lesions within FiCTION and how this related to their everyday experiences of doing dentistry.

Methods

Overall, 31 DPs from FiCTION-trained dental surgeries in four regions of the UK participated in semi-structured interviews about their experiences of the three treatment arms (conventional management of carious lesions and prevention (C + P), biological management of carious lesions and prevention (B + P) or prevention alone (PA)). A theoretical framework, drawing on social practice theory (SPT), was developed for analysis.

Results

Participants discussed perceived effectiveness of, and familiarity with, the three techniques. The C + P arm was familiar, but some participants questioned the effectiveness of conventional restorations. Attitudes towards the B + P arm varied in terms of familiarity, but once DPs were introduced to the techniques, this was seen as effective. While prevention was familiar, PA was described as ineffective. DPs manage children with carious lesions day-to-day, drawing on previous experience and knowledge of the child to provide what they view as the most appropriate treatment in the best interests of each child. Randomisation undermined these normal choices. Several DPs reported deviating from the trial arms in order to treat a patient in a particular way. Participants valued evidence-based dentistry, and expect to use the results of FiCTION to inform future practice. They anticipate continuing to use the full range of treatment options, and to personally select appropriate strategies for individual children.

Conclusions

RCTs take place in the context of day-to-day practices of doing dentistry. DPs employ experiential and interpersonal knowledge to act in the best interests of their patients. Randomisation within a clinical trial can present a source of tension for DPs, which has implications for assuring individual equipoise in future trials.

Cost-effectiveness of child caries management: a randomised controlled trial (FiCTION trial)

BACKGROUND

A three-arm parallel group, randomised controlled trial set in general dental practices in England, Scotland, and Wales was undertaken to evaluate three strategies to manage dental caries in primary teeth. Children, with at least one primary molar with caries into dentine, were randomised to receive Conventional with best practice prevention (C + P), Biological with best practice prevention (B + P), or best practice Prevention Alone (PA).

METHODS

Data on costs were collected via case report forms completed by clinical staff at every visit. The co-primary outcomes were incidence of, and number of episodes of, dental pain and/or infection avoided. The three strategies were ranked in order of mean cost and a more costly strategy was compared with a less costly strategy in terms of incremental cost-effectiveness. Costs and outcomes were discounted at 3.5%.

RESULTS

A total of 1144 children were randomised with data on 1058 children (C + P n = 352, B + P n = 352, PA n = 354) used in the analysis. On average, it costs £230 to manage dental caries in primary teeth over a period of up to 36 months. Managing children in PA was, on average, £19 (97.5% CI: -£18 to £55) less costly than managing those in B + P. In terms of effectiveness, on average, there were fewer incidences of, (- 0.06; 97.5% CI: - 0.14 to 0.02) and fewer episodes of dental pain and/or infection (- 0.14; 97.5% CI: - 0.29 to 0.71) in B + P compared to PA. C + P was unlikely to be considered cost-effective, as it was more costly and less effective than B + P.

CONCLUSIONS

The mean cost of a child avoiding any dental pain and/or infection (incidence) was £330 and the mean cost per episode of dental pain and/or infection avoided was £130. At these thresholds B + P has the highest probability of being considered cost-effective. Over the willingness to pay thresholds considered, the probability of B + P being considered cost-effective never exceeded 75%.

TRIAL REGISTRATION

The trial was prospectively registered with the ISRCTN (reference number ISRCTN77044005) on the 26th January 2009 and East of Scotland Research Ethics Committee provided ethical approved (REC reference: 12/ES/0047).

Effect of altitude on urinary, plasma and nail fluoride levels in children and adults in Nepal

INTRODUCTION

A greater prevalence of dental fluorosis has been reported in higher- versus lower-altitude communities. This study, for the first time, examined several aspects of fluoride metabolism in children, aged 4-5 years, and their parent, living at lower altitude (<78 m) and higher altitude (>1487) areas in Nepal.

METHODS

The study assessed total daily fluoride intake (TDFI), 24 h urinary fluoride excretion (UFE), and fluoride concentrations of toe- and finger-nail (FC_toenail, FC_fingernail) in children and parents as well as fluoride concentration of plasma (FC_plasma) in parents. Fractional urinary fluoride excretion (FUFE) was calculated as the ratio between UFE and TDFI. FC_toenail, FC_fingernail and FC_plasma were normalised for TDFI by dividing the variables by TDFI and the ratio was reported as the percentage.

RESULTS

In total, 89 children and 80 parents took part in the study: 42 children and 41 parents from the lower altitude area; 47 children and 39 parents from the higher altitude area. Fluoride concentration of drinking water was significantly (P < 0.001) higher at lower altitude (0.395 mg F/l) than at higher altitude (0.104 mg F/l). TDFI was significantly (p < 0.001) higher in both children and parents living in lower altitude than those living at higher altitude. There was a statistically significant (p = 0.044) difference in the mean FUFE of children living at lower altitude (53%) and higher altitude (46%). However, no significant difference in FUFE was found between parents living at lower altitude (47%) compared with higher altitude (41%). In both children and parents, no statistically significant differences in normalised FC_toenail, FC_fingernail were found between the two altitude areas. However, normalised FC_plasma was statistically significantly (P = 0.005) higher in parents living at higher altitude (0.15%) compared with those living at lower altitude (0.11%).

CONCLUSION

The results suggest that higher altitude living results in decreased urinary fluoride excretion, and consequently increased fluoride retention in children for a given dose (amount) of fluoride.

Best-practice prevention alone or with conventional or biological caries management for 3- to 7-year-olds: the FiCTION three-arm RCT

BACKGROUND

Historically, lack of evidence for effective management of decay in primary teeth has caused uncertainty, but there is emerging evidence to support alternative strategies to conventional fillings, which are minimally invasive and prevention orientated.

OBJECTIVES

The objectives were (1) to assess the clinical effectiveness and cost-effectiveness of three strategies for managing caries in primary teeth and (2) to assess quality of life, dental anxiety, the acceptability and experiences of children, parents and dental professionals, and caries development and/or progression.

DESIGN

This was a multicentre, three-arm parallel-group, participant-randomised controlled trial. Allocation concealment was achieved by use of a centralised web-based randomisation facility hosted by Newcastle Clinical Trials Unit.

SETTING

This trial was set in primary dental care in Scotland, England and Wales.

PARTICIPANTS

Participants were NHS patients aged 3-7 years who were at a high risk of tooth decay and had at least one primary molar tooth with decay into dentine, but no pain/sepsis.

INTERVENTIONS

Three interventions were employed: (1) conventional with best-practice prevention (local anaesthetic, carious tissue removal, filling placement), (2) biological with best-practice prevention (sealing-in decay, selective carious tissue removal and fissure sealants) and (3) best-practice prevention alone (dietary and toothbrushing advice, topical fluoride and fissure sealing of permanent teeth).

MAIN OUTCOME MEASURES

The clinical effectiveness outcomes were the proportion of children with at least one episode (incidence) and the number of episodes, for each child, of dental pain or dental sepsis or both over the follow-up period. The cost-effectiveness outcomes were the cost per incidence of, and cost per episode of, dental pain and/or dental sepsis avoided over the follow-up period.

RESULTS

A total of 72 dental practices were recruited and 1144 participants were randomised (conventional arm, n = 386; biological arm, n = 381; prevention alone arm, n = 377). Of these, 1058 were included in an intention-to-treat analysis (conventional arm, n = 352; biological arm, n = 352; prevention alone arm, n = 354). The median follow-up time was 33.8 months (interquartile range 23.8-36.7 months). The proportion of children with at least one episode of pain or sepsis or both was 42% (conventional arm), 40% (biological arm) and 45% (prevention alone arm). There was no evidence of a difference in incidence or episodes of pain/sepsis between arms. When comparing the biological arm with the conventional arm, the risk difference was -0.02 (97.5% confidence interval -0.10 to 0.06), which indicates, on average, a 2% reduced risk of dental pain and/or dental sepsis in the biological arm compared with the conventional arm. Comparing the prevention alone arm with the conventional arm, the risk difference was 0.04 (97.5% confidence interval -0.04 to 0.12), which indicates, on average, a 4% increased risk of dental pain and/or dental sepsis in the prevention alone arm compared with the conventional arm. Compared with the conventional arm, there was no evidence of a difference in episodes of pain/sepsis among children in the biological arm (incident rate ratio 0.95, 97.5% confidence interval 0.75 to 1.21, which indicates that there were slightly fewer episodes, on average, in the biological arm than the conventional arm) or in the prevention alone arm (incident rate ratio 1.18, 97.5% confidence interval 0.94 to 1.48, which indicates that there were slightly more episodes in the prevention alone arm than the conventional arm). Over the willingness-to-pay values considered, the probability of the biological treatment approach being considered cost-effective was approximately no higher than 60% to avoid an incidence of dental pain and/or dental sepsis and no higher than 70% to avoid an episode of pain/sepsis.

CONCLUSIONS

There was no evidence of an overall difference between the three treatment approaches for experience of, or number of episodes of, dental pain or dental sepsis or both over the follow-up period.

FUTURE WORK

Recommendations for future work include exploring barriers to the use of conventional techniques for carious lesion detection and diagnosis (e.g. radiographs) and developing and evaluating suitable techniques and strategies for use in young children in primary care.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN77044005.

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. 24, No. 1. See the NIHR Journals Library website for further project information.

Child Caries Management: A Randomized Controlled Trial in Dental Practice

This multicenter 3-arm, parallel-group, patient-randomized controlled trial compared clinical effectiveness of 3 treatment strategies over 3 y for managing dental caries in primary teeth in UK primary dental care. Participants aged 3 to 7 y with at least 1 primary molar with dentinal carious lesion were randomized across 3 arms (1:1:1 via centrally administered system with variable-length random permuted blocks): C+P, conventional carious lesion management (complete carious tooth tissue removal and restoration placement) with prevention; B+P, biological management (sealing in carious tooth tissue restoratively) with prevention; and PA, prevention alone (diet, plaque removal, fluorides, and fissure sealants). Parents, children, and dentists were not blind to allocated arm. Co–primary outcomes were 1) the proportion of participants with at least 1 episode of dental pain and/or infection and 2) the number of episodes of dental pain and/or infection during follow-up (minimum, 23 mo). In sum, 1,144 participants were randomized (C+P, n = 386; B+P, n = 381; PA, n = 377) by 72 general dental practitioners, of whom 1,058 (C+P, n = 352; B+P, n = 352; PA, n = 354) attended at least 1 study visit and were included in the primary analysis. The median follow-up was 33.8 mo (interquartile range, 23.8 to 36.7). Proportions of participants with at least 1 episode of dental pain and/or infection were as follows: C+P, 42%; B+P, 40%; PA, 45%. There was no evidence of a difference in incidence of dental pain and/or infection when B+P (adjusted risk difference [97.5% CI]: −2% [−10% to 6%]) or PA (4% [−4% to 12%]) was compared with C+P. The mean (SD) number of episodes of dental pain and/or infection were as follows: C+P, 0.62 (0.95); B+P, 0.58 (0.87); and PA, 0.72 (0.98). Superiority could not be concluded for number of episodes between B+P (adjusted incident rate ratio (97.5% CI): 0.95 [0.75 to 1.21]) or PA (1.18 [0.94 to 1.48]) and C+P. In conclusion, there was no evidence of a difference among the 3 treatment approaches for incidence or number of episodes of dental pain and/or infection experienced by these participants with high caries risk and established disease (trial registration: ISRCTN77044005).

The use of urinary fluoride excretion to facilitate monitoring fluoride intake: A systematic scoping review

BACKGROUND

As a recognised effective and economical agent for dental caries prevention, fluoride has been used in many different fluoridation schemes implemented across the world. Considering the narrow 'dose-gap' between the benefit of caries reduction and the risk of dental fluorosis, it is recommended that fluoride intake is monitored by measuring urinary fluoride excretion. The aim of this scoping review is to map the current literature/evidence on fluoride intake and excretion studies in relation to the study population, settings, type of study design, methodology, and analytical approach.

METHODS

Embase/Ovid, MEDLINE/Ovid, CINAHL/EBSCO, Scopus/Elsevier were searched for relevant articles until April 2018. Studies were included if they reported intake and excretion of fluoride in healthy humans of all age groups. Findings were explored using a narrative synthesis to summarise studies characteristics and outcome measures.

RESULTS

Removal of duplicates from the originally 2295 identified records yielded 1093 studies of which 206 articles were included. Only 21.6% of the studies were conducted in children (<8-year-olds). Most studies (38.8%) used drinking water concentration as a proxy for fluoride intake, whereas only 11.7% measured fluoride intake from all sources. Of the 72 studies that measured dietary fluoride intake, only 10 reported the validity of the employed dietary assessment method. Only 14 studies validated the urine sample collection methods. No information on the validity of the employed analytical method was reported by the majority (64.6%) of studies. Only a small proportion (8.7%) of the included studies investigated the association between fluoride intake and excretion.

CONCLUSION

The findings reveal much variability in terms of conducting the studies and reporting the findings, illustrating a high heterogeneity in data collection across settings and populations. Future studies should provide more detail on sampling technique, measurement protocols (including validation), and on clearly defining the relationship between intake and urinary excretion of fluoride.

A Comparison of Simple Analytical Methods for Determination of Fluoride in Microlitre-Volume Plasma Samples

The aim was to compare potential methods for fluoride analysis in microlitre-volume plasma samples containing nano-gram amounts of fluoride. Methods: A group of 4 laboratories analysed a set of standardised biological samples as well as plasma to determine fluoride concentration using 3 methods. In Phase-1, fluoride analysis was carried out using the established hexamethyldisiloxane (HMDS)-diffusion method (1 mL-aliquot/analysis) to obtain preliminary measurement of agreement between the laboratories. In Phase-2, the laboratories analysed the same samples using a micro-diffusion method and known-addition technique with 200 µL-aliquot/analysis. Coefficients of Variation (CVs) and intra-class correlation coefficients (ICCs) were estimated using analysis of variance to evaluate the amount of variation within- and between-laboratories. Based on the results of the Phase-2 analysis, 20 human plasma samples were analysed and compared using the HMDS-diffusion method and known-addition technique in Phase-3. Results: Comparison of Phase-1 results showed no statistically significant difference among the laboratories for the overall data set. The mean between- and within-laboratory CVs and ICCs were < 0.13 and ≥0.99, respectively, indicating very low variability and excellent reliability. In Phase-2, the overall results for between-laboratory variability showed a poor CV (1.16) and ICC (0.44) for the micro-diffusion method, whereas with the known-addition technique the corresponding values were 0.49 and 0.83. Phase-3 results showed no statistically significant difference in fluoride concentrations of the plasma samples measured with HMDS-diffusion method and known- addition technique, with a mean (SE) difference of 0.002 (0.003) µg/mL. In conclusion, the known-addition technique could be a suitable alternative for the measurement of fluoride in plasma with microlitre-volume samples.

Using Normalisation Process Theory to investigate the implementation of school-based oral health promotion

Despite the considerable improvement in oral health of children in the UK over the last forty years, a significant burden of dental caries remains prevalent in some groups of children, indicating the need for more effective oral health promotion intervention (OHPI) strategies in this population.

OBJECTIVE

To explore the implementation process of a community-based OHPI, in the North East of England, using Normalisation Process Theory (NPT) to provide insights on how effectiveness could be maximised.

METHODS

Utilising a generic qualitative research approach, 19 participants were recruited into the study. In-depth interviews were conducted with relevant National Health Service (NHS) staff and primary school teachers while focus group discussions were conducted with reception teachers and teaching assistants. Analyses were conducted using thematic analysis with emergent themes mapped onto NPT constructs.

RESULTS

Participants highlighted the benefits of OHPI and the need for evidence in practice. However, implementation of 'best evidence' was hampered by lack of adequate synthesis of evidence from available clinical studies on effectiveness of OHPI as these generally have insufficient information on the dynamics of implementation and how effectiveness obtained in clinical studies could be achieved in 'real life'. This impacted on the decision-making process, levels of commitment, collaboration among OHP teams, resource allocation and evaluation of OHPI.

CONCLUSIONS

A large gap exists between available research evidence and translation of evidence in OHPI in community settings. Effectiveness of OHPI requires not only an awareness of evidence of clinical effectiveness but also synthesised information about change mechanisms and implementation protocols.

Fluoride intake and urinary fluoride excretion in 4- and 8-year-old children living in urban and rural areas of Southwest Nigeria

OBJECTIVES

To estimate and compare total daily fluoride intake (TDFI), daily urinary fluoride excretion (DUFE), daily fluoride retention (DFR), fractional urinary fluoride excretion (FUFE) and fractional fluoride retention (FFR) in 4- and 8 year-old Nigerians and explore associations between these outcomes to improve understanding of fluoride metabolism.

METHODS

Using a cross-sectional observational study, 72 four-year-olds and 72 eight-year-olds were recruited from nursery and primary schools (respectively) in lower and higher water F areas of urban and rural localities in Oyo State, southwest Nigeria. TDFI from diet and toothpaste ingestion was assessed using a validated Food Frequency Questionnaire and visual scale of toothpaste used during toothbrushing. DUFE was measured by collecting a 24-hour urine sample, FUFE estimated as the ratio between DUFE and TDFI, DFR estimated as TDFI-TDFE (where TDFE = DUFE + estimated faecal F excretion (ie TDFI × 10%), and FFR was estimated as [(TDFI-DFR)/TDFI] × 100. Data were analysed using ANOVA with post hoc tests and Student's t tests and strengths of associations between key variables measured.

RESULTS

Mean (SD) TDFI, DUFE, DFR, FUFE and FFR were 0.137 (0.169) mg/kg bw/d, 0.032 (0.027) mg/kg bw/d, 0.091 (0.147) mg/kg bw/d, 44% (44%) and 46% (44%), respectively, for 4-year-olds. Corresponding values for 8-year-olds (n = 63) were 0.106 (0.130) mg/kg bw/d, 0.022 (0.017) mg/kg bw/d, 0.073 (0.107) mg/kg bw/d, 36% (30%) and 54% (30%), respectively. Dietary contribution to TDFI was 79% and 75% (respectively), for 4- and 8-year-olds. Mean (SD) TDFI from toothpaste ingestion was 0.021 (0.013) mg/kg bw/d in 4-year-olds, 0.014 (0.010) mg/kg bw/d in 8-year-olds (P = .002) but with no differences between areas. Differences in dietary F intake determined the main differences in F exposure between areas. The positive correlation between TDFI and DUFE was weak for 4-year-olds (r = +.29) and strong for 8-year-olds (r = +.64). A strong positive correlation was observed between TDFI and DFR for both age groups: (r) = +.98 for 4-year-olds and (r) = +.99 for 8-year-olds.

CONCLUSION

Fluoride intake in these 4- and 8-year-old Nigerians was much higher than the "optimal range" of 0.05-0.07 mg/kg bw/d in rural, higher F water areas, with diet as the main contributor. F retention was similar in both age groups, with almost half of TDFI retained in the body. In terms of risk vs benefit for fluorosis and dental caries, this finding should be considered when mitigating against excessive fluoride exposure and planning F-based prevention.

Comparison of total ionic strength adjustment buffers III and IV in the measurement of fluoride concentration of teas

Background:

Tea is the second most consumed drink in the UK and a primary source of hydration; it is an important source of dietary fluoride (F) for consumers and also abundant in aluminium (Al). Varying ranges of F concentrations in teas have been reported worldwide which may be, in part, due to differences in analytical techniques used to measure this ion.

Aim:

The effect of using total ionic adjustment buffers (TISAB) III or IV when measuring F concentration of black teas available in the UK was investigated and compared. Based on this evaluation, the effects of three different infusion times, 1 min, 10 min and 1 h, caffeine content and tea form on the F contents of the tea samples were investigated.

Methods:

The F concentrations of 47 tea samples were measured directly using a fluoride ion-selective electrode (F-ISE), TISAB III and IV and infusion times of 1 min, 10 min and 1 h.

Results:

Mean (SD) F concentration of tea samples for all infusion times was statistically significantly higher (p < 0.001) measured by TISAB IV (4.37 (2.16) mg/l) compared with TISAB III (3.54 (1.65) mg/l). A statistically significant positive correlation (p < 0.001) was found between Al concentration (mg/l) and differences in F concentration (mg/l) measured using the two TISABs; the difference in F concentration measured by the two TISABs increased with the magnitude of Al concentration.

Conclusion:

Due to higher concentrations of F and Al in teas and their complexing potential, use of TISAB IV facilitates more accurate measurement of F concentration when using an F-ISE and a direct method.

Effect of chronic exercise on fluoride metabolism in fluorosis-susceptible mice exposed to high fluoride

The present study investigated the effect of chronic exercise on fluoride (F) metabolism in fluorosis-susceptible mice exposed to high-F and explored the relationship between F concentrations in bone and plasma. Thirty male mice were randomised into three groups: Group I (No-F, No-Exercise), Group II (50 ppmF, No-Exercise), Group III (50 ppmF, Exercise). Body weight and physical performance of all mice were measured at baseline and end of experiment. F concentrations of plasma and bone were measured at the end of experiment. Mean plasma F concentration was significantly higher (p < 0.001) in Groups II and III compared with Group I. Mean bone F concentration was also significantly higher (p < 0.01) in Groups II and III compared with Group I. There was a significant correlation (p = 0.01, r = 0.54) between F concentration of plasma and bone. Mean body weight of Group I mice was significantly higher than Group II (p < 0.001) and Group III (p = 0.001) mice at the end of the experiment. This study, which provides the first data on the effect of chronic exercise on F metabolism in fluorosis-susceptible mice, suggests no effect of chronic exercise on F in plasma and bone. However, exposure to high-F resulted in lower body weight and exercise capacity in mice.

Prevalence and extent of enamel defects in the permanent teeth of 8-year-old Nigerian children

OBJECTIVES

Enamel formation is a vulnerable developmental process, susceptible to environmental influences such as excessive systemic fluoride (F) exposure and infant/childhood disease. This study determined prevalence and extent of developmental enamel defects (DDE) and dental fluorosis in 8-year-old Nigerians and explored associations with key predictors.

METHODS

A sample of 322 healthy 8-year-olds (155 males, 167 females) from primary schools in lower and higher water F areas of (i) rural and (ii) urban parts of Oyo State in south-west Nigeria (n = 4 areas) (in which the mean (SD) F concentration of community water supplies ranged from 0.07 (0.02) to 2.13 (0.64) mg F/L) were dentally examined using modified DDE (mDDE) and Thylstrup and Fejerskov (TF) indices. Drinking waters, cooking waters and toothpaste samples were analysed for F concentration using a F ion-selective electrode (F-ISE). Information on infant/childhood diseases, infant feeding and tooth cleaning practices was obtained from parents/legal guardians. Data were analysed using ANOVA, chi-square tests, Spearman correlation and binary logistic regression as appropriate.

RESULTS

Mean (SD) F concentration of actual drinking and actual cooking waters consumed by participants was 0.25 (0.20) and 0.24 (0.14) mg F/L respectively in the urban higher F area; 1.11 (1.00) and 1.16 (1.02) mg F/L, respectively in the rural higher F area (P < .05). Overall, mouth prevalence of DDE in the permanent dentition was 61.2% with a mean (SD) of 2.4 (2.2) index teeth affected. Dental fluorosis mouth prevalence was 29.8% with a mean of 2.1 (3.7) teeth affected. Prevalence and extent of DDE and dental fluorosis were greater in higher F than lower water F areas (P < .001). A weak positive correlation was seen between extent of dental fluorosis and drinking water F concentration (ρ = 0.28). The absence of infant/childhood disease was associated with a lower risk of DDE being present (P = .001), with an odds ratio of 0.43 (95% CI = 0.26, 0.71). Gender was a statistically significant (P = .014) predictor for dental fluorosis with females having a higher risk OR 1.94 (95% CI = 1.14, 3.28) of dental fluorosis than males.

CONCLUSIONS

In these Nigerian 8-year-olds (n = 322), mouth prevalence of DDE was 61.2% (mean (SD) teeth affected = 2.4 (2.2)), and a key positive predictor was a history of infant/childhood disease. With 29.8% of these children exhibiting dental fluorosis (mean (SD) teeth affected = 2.1(3.7)), drinking water F concentration was identified as a positive predictor, along with gender, with females more at risk of dental fluorosis than males.

Group O low titre only emergency donor panels for small combat teams

INTRODUCTION

Military elements increasingly operate in small teams in remote areas with no immediate blood product support. Planners and operators may endorse collection of fresh whole blood from pretested donors in emergency situations. The biggest risk of transfusion is the accidental use of ABO incompatible blood which can be fatal. The risk may be mitigated by using only group O LOw (OLO) titre donors with plasma containing low levels of the naturally occurring antibody to group A and B red cells. This paper reviews the ABO blood group distribution in potential blood donors from a high readiness UK medical regiment and explores the feasibility of using only group OLO donors in small teams.

METHODS

A retrospective review of routine volunteer blood donor samples was undertaken at 6 monthly intervals during a 2-year period. Personnel were tested in groups when available during training to create multiple donor panels to simulate small teams.

RESULTS

206 donation samples were collected from 157 potential donors. All donors were acceptable based on the lifestyle questionnaire, serology and microbiology screen. Of the 206 samples reviewed, 85 (41%) were group O (D pos and D neg). 14 group O (16.5%) were shown to have high titre of anti-A or B. Therefore, 71, that is, 34% overall were suitable as OLO donors. The donor panel size varied from 15 to 44. The absolute number of OLO donors in each panel ranged from 4 to 17 and the number of O neg donors was 0-3.

CONCLUSION

A third of samples were suitable as OLO donors; however, there were insufficient 'universal' donors within smaller subgroups (<10). In this situation, we recommend the careful use of both group O and group A donors or the use of a buddy-buddy blood group matrix.

Determining an Upper Reference Value for the Urinary Fluoride-Creatinine Ratio in Healthy Children Younger than 7 Years

The urinary fluoride/creatinine ratio (UF/Cr) in a spot urine sample could be a useful systemic F exposure monitoring tool. No reference value for UF/Cr currently exists, therefore this study aimed to establish an upper reference value for a UF/Cr, corresponding to excessive systemic F exposure, i.e., >0.07 mg F/kg body weight (b.w.)/day, in children. Subsidiary aims were to examine the relationship between (i) total daily F intake (TDFI) and 24-h urinary F excretion (DUFE); (ii) DUFE and UF/Cr, and (iii) TDFI and UF/Cr. Simultaneously collected TDFI, DUFE, and urinary creatinine (UCr) data in children <7 years were taken from UK studies conducted from 2002 to 2014 in order to calculate UF/Cr (mg/g) for each child. For the 158 children (mean age 5.8 years) included in the data analysis, mean TDFI and DUFE were 0.049 (SD 0.033) and 0.016 (SD 0.008) mg/kg b.w./day, respectively, and the mean UF/Cr was 1.21 (SD 0.61) mg/g. Significant (p < 0.001) positive linear correlations were found between TDFI and DUFE, DUFE and UF/Cr, and TDFI and UF/Cr. The estimated upper reference value for UF/Cr was 1.69 mg/g; this was significantly (p = 0.019) higher than the UF/Cr (1.29) associated with optimal F exposure (0.05-0.07 mg/kg b.w./day). In conclusion, the strong positive correlation between TDFI and UF/Cr confirms the strong association of these 2 F exposure variables and the value of a spot urine sample for prediction of TDFI (i.e., the most important risk factor in determining fluorosis occurrence and severity) in young children. Establishing an estimation of an upper reference value of 1.69 mg/g for UF/Cr in spot urine samples could simplify and facilitate their use as a valuable tool in large epidemiological studies.

The use of adjunctive antipsychotics to treat depression in UK primary care

OBJECTIVE

Adjunctive antipsychotic therapy can be prescribed to patients with depression who have inadequate response to antidepressants. This study aimed to describe the use of adjunctive antipsychotics over a time period that includes the authorization in 2010 of prolonged-release quetiapine as the first adjunct antipsychotic to be used in major depressive disorder in the UK.

RESEARCH DESIGN AND METHODS

Adults with an episode of depression between January 1, 2005 and July 31, 2013 were identified from antidepressant prescriptions and depression diagnoses in the UK Clinical Practice Research Datalink. Patients with prior records of bipolar disorder, schizophrenia, or antipsychotic prescriptions were excluded.

MAIN OUTCOME MEASURES

Rates of adjunct antipsychotic initiation and characteristics and management of patients with adjunct antipsychotics.

RESULTS

Of 224,353 adults with depression, 5,807 (2.6%) initiated adjunct antipsychotic therapy. Overall incidence of antipsychotic initiation was 7.4 per 1,000 patient-years (95% CI = 7.2-7.6). Between 2005-2013, the overall rate did not change, although initiation of typical antipsychotic prescribing decreased (57.7% to 29.1%), while atypical antipsychotics, especially quetiapine (14.1% to 49.7%), increased. Of those who initiated antipsychotics, 59.4% were women (typical antipsychotics = 62.8%, atypical antipsychotics = 56.1%) and median age was 46 years (typicals = 49 years, atypicals = 44 years).

CONCLUSIONS

Antipsychotics were rarely used to treat depression between 2005-2013 in UK primary care. The choice of adjunctive antipsychotic therapy changed over this time, with atypical antipsychotics now representing the preferred treatment choice. However, information on patients strictly cared for in other settings, such as by psychiatrists or in hospitals, potentially more severe patients, was unavailable and may differ. Nonetheless, the high off-label use in primary care, even after the authorization of quetiapine, suggests that there is a need for more licensed treatment options for adjunctive antipsychotic therapy in major depressive disorder.

Are Volunteering and Caregiving Associated with Suicide Risk? A Census-based Longitudinal Study

Background

This record linkage study explores the suicide risk of people engaged in caregiving and volunteering. Theory suggests opposing risks as volunteering is associated with better mental health and caregiving with a higher prevalence and incidence of depression.

Methods

A 2011 census-based study of 1,018,000 people aged 25–74 years (130,816 caregivers and 110,467 volunteers; 42,099 engaged in both). All attributes were based on census records. Caregiving was categorised as either light (1–19 hours/week) or more intense (20+ hours/week). Suicide risk was based on 45 months of death records and assessed using Cox proportional hazards models with adjustment for and stratification by mental health status at census.

Results

More intense caregiving was associated with worse mental health (ORadj = 1.15: 95%CI = 1.12, 1.18); volunteering with better mental health (OR 0.87; 95%CIs 0.84, 0.89). The cohort experienced 528 suicides during follow-up. Both volunteering and caregiving were associated with a lower risk of suicide though this was modified by baseline mental ill-health (P = 0.003), HR 0.66; 95%CIs 0.49, 0.88 for those engaged in either activity and with good mental health at baseline and HR 1.02; 95%CIs 0.69, 1.51 for their peers with poor mental health. There was some indication that those engaged in both activities had the lowest suicide risk (HR 0.34; 95%CIs 0.14, 0.84).

Conclusions

Despite the poorer mental health amongst caregivers they are not at increased risk of suicide. The significant overlap between caregiving and volunteering and the lower risk of suicide for those engaged in both activities may indicate a synergism of action.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Fluoride concentrations in a range of ready-to-drink beverages consumed in Heilongjiang Province, north-east China

Consumption of ready-to-drink beverages, as a potential source of fluoride (F), has increased considerably in China over the last decade. To help inform the public and policy makers, this study aimed to measure F concentration of ready-to-drink beverages on sale in Heilongjiang province, north east China. Three batches of 106 drink products manufactured by 26 companies were purchased from the main national supermarkets in Harbin, Heilongjiang province, China. The F concentration of all samples was determined, in triplicate, using a fluoride ion-selective electrode in conjunction with a meter and a direct method of analysis. The products were categorised into 10 groups according to product type. F concentrations of the samples ranged from 0.012-1.625 mg/l with a mean of 0.189 mg/l and a median of 0.076 mg/l. More than half of the products (55%) had an F concentration of ≤0.1 mg/l, while <5% had a F concentration of >0.7 mg/l. The 'tea with milk' group contained the highest mean F concentration (1.350 mg/l), whereas the lowest mean F concentration (0.027 mg/l) was found for the 'fruit juice' group. For some products, such as tea, fruit juice and carbonated beverages, there were substantial variations in F concentration between batches, manufacturers and production sites. In conclusion, ready-to-drink products (apart from tea), sold in Heilongjiang province, China, when consumed in moderation are unlikely to constitute a substantial risk factor for the development of dental or skeletal fluorosis.

Abstract P1-05-18: Genomic copy number alterations (CNA) associated with pCR in HER2-positive (HER2+) early-stage breast cancer (BrCa) patients receiving neoadjuvant trastuzumab (T)

Introduction: Genetic alterations such as amplifications and deletions frequently contribute to tumorigenesis. These alterations can change gene expression which alters the normal cell growth and survival regulatory mechanisms. Characterisation of DNA copy number alterations (CNA) is important to understand cancer progression and response to therapy. The aim of this study is to determine patterns of CNAs in HER2+ early-stage BrCa patients achieving pathological complete response (pCR) to neoadjuvant T therapy.

Methods: Retrospective analysis of our database of 95 HER2+ BrCa (stages I-III) who received T neoadjuvantly revealed 46 % (44/95) achieved pCR compared with 53 % (51/95) who did not respond (NR). DNA from pre-treatment tumour biopsy specimens from neoadjuvant T therapy patients was extracted, and array-based comparative genomic hybridization (aCGH, n = 8; 6 pCR:2 NR) was used to identify CNAs, which correlated with pCR. Pathway analysis was then used to identify functionally relevant genes in aberrant regions.

Results: aCGH analysis of DNA from pCR and NR identified distinct patterns of CNAs. HER2 amplicon was confirmed by IHC and aCGH in all samples. Although there was no significant difference in the average CNAs between groups (20±17 vs 17±2), there was greater variation in the range of CNAs in pCR (8-56 CNA) compared to NR (15-19 CNA). More gains and amplifications were observed in pCR patients with more deletions in the NR group. The most common chromosomal amplification region included chr8q12.1-q24 with 87.5% of all cases displaying gains. Of the 6 patients who achieved pCR, 50% displayed a deletion in chr9 spanning p24.3-p21.3, consistent with a deletion of tumour suppressor CDKN2A. No aberrations in chr9 were observed in NR cohort. The deleted genomic region contained 65 common protein-coding genes, with the interferon biological pathway as the most significant (p=1.03E-36).

Conclusions: Distinct genomic CNAs were observed between patients achieving pCR compared to NR. However, of the 8 pts characterised here, none have relapsed. Follow-up data revealed a relapse rate of 6.8 % (3/44) vs 11.8 % (6/51) in the pCR and NR groups, respectively. To further elucidate the immunological response, we will present CNA data patterns on relapse and response and compare the impact of CNAs, immune-related proteins and pCR as surrogate predictors for outcome.

Citation Format: Walsh N, Gullo G, Maguire A, O'Donovan N, Quinn C, Crown J. Genomic copy number alterations (CNA) associated with pCR in HER2-positive (HER2+) early-stage breast cancer (BrCa) patients receiving neoadjuvant trastuzumab (T) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-18.

Bioavailability of Fluoride in Drinking Water: a Human Experimental Study

It has been suggested that systemic fluoride absorption from drinking water may be influenced by the type of fluoride compound in the water and by water hardness. Using a human double-blind cross-over trial, we conducted this study to measure cmax, Tmax, and Area Under the Curve (AUC) for plasma F concentration against time, following the ingestion of naturally fluoridated hard and soft waters, artificially fluoridated hard and soft waters, and a reference water. Mean AUC over 0 to 8 hours was 1330, 1440, 1679, 1566, and 1328 ng F•min•mL−1 for naturally fluoridated soft, naturally fluoridated hard, artificially fluoridated soft, artificially fluoridated hard, and reference waters, respectively, with no statistically significant differences among waters for AUC, cmax, or Tmax. Any differences in fluoride bioavailability between drinking waters in which fluoride is present naturally or added artificially, or the waters are hard or soft, were small compared with large within- and between-subject variations in F absorption. Abbreviations used: F, fluoride; AUC, Area under the Curve for plasma F concentration against time; AUC(0-3), Area under the Curve for plasma F concentration against time for 0 to 3 hours following water ingestion; AUC(0-8), Area under the Curve for plasma F concentration against time for 0 to 8 hours following water ingestion; cmax, maximum plasma F concentration corrected for baseline plasma F and dose ( i.e., F concentration of individual waters); Tmax, time of cmax.

Development of a Database of the Fluoride Content of Selected Drinks and Foods in the UK

It is important to monitor systemic fluoride (F) intake from foods, drinks and inadvertent toothpaste ingestion in order to minimise the risk of dental fluorosis while maximising caries prevention. In the UK, an F database containing the F content of commercially available foods and drinks was compiled from 518 products analysed using an acid-diffusion method and F-ion-selective electrode. The individual products analysed ranged from <0.01 µg F/100 g for butter/margarine (miscellaneous foods group) to 1,054.20 µg F/100 g for canned sardines (fish group). These findings, along with the wide range of F contents found within the food groups, highlight the need for comprehensive F content labelling of food and drink products.

Effect of exercise on fluoride metabolism in adult humans: a pilot study

An understanding of all aspects of fluoride metabolism is critical to identify its biological effects and avoid fluoride toxicity in humans. Fluoride metabolism and subsequently its body retention may be affected by physiological responses to acute exercise. This pilot study investigated the effect of exercise on plasma fluoride concentration, urinary fluoride excretion and fluoride renal clearance following no exercise and three exercise intensity conditions in nine healthy adults after taking a 1-mg Fluoride tablet. After no, light, moderate and vigorous exercise, respectively, the mean (SD) baseline-adjusted i) plasma fluoride concentration was 9.6(6.3), 11.4(6.3), 15.6(7.7) and 14.9(10.0) ng/ml; ii) rate of urinary fluoride excretion over 0-8 h was 46(15), 44(22), 34(17) and 36(17) μg/h; and iii) rate of fluoride renal clearance was 26.5(9.0), 27.2(30.4), 13.1(20.4) and 18.3(34.9) ml/min. The observed trend of a rise in plasma fluoride concentration and decline in rate of fluoride renal clearance with increasing exercise intensity needs to be investigated in a larger trial. This study, which provides the first data on the effect of exercise with different intensities on fluoride metabolism in humans, informs sample size planning for any subsequent definitive trial, by providing a robust estimate of the variability of the effect.

INVESTIGATING THE MANAGEMENT OF CARIOUS PRIMARY TEETH IN GENERAL DENTAL PRACTICE: AN OVERVIEW OF THE DEVELOPMENT AND CONDUCT OF THE FICTION TRIAL

The management of carious primary teeth is a challenge for patients, parents and clinicians. Most evidence supporting different management strategies originates from a specialist setting and therefore its relevance to the primary care setting is questionable. The UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) has commissioned the FiCTION (Filling Children's Teeth: Indicated Or Not?) trial; a multi-centre primary dental care randomised controlled trial (RCT) to determine the most clinically and cost- effective approach to managing caries in the primary dentition in the UK. This large trial began in 2012, is due to be completed in late 2017 and involves 72 practices and 1,124 children initially aged three to seven years with dentine caries, following randomisation to one of three caries management strategies. Clinical, radiographic, quality of life, treatment acceptability and health economics data are collected during the three-year follow up period. This article provides an overview of the development and conduct of FiCTION and discusses some approaches adopted to manage challenges and achieve the patient recruitment target.

Spatial variation of the colonic microbiota in patients with ulcerative colitis and control volunteers

OBJECTIVES

The relevance of spatial composition in the microbial changes associated with UC is unclear. We coupled luminal brush samples, mucosal biopsies and laser capture microdissection with deep sequencing of the gut microbiota to develop an integrated spatial assessment of the microbial community in controls and UC.

DESIGN

A total of 98 samples were sequenced to a mean depth of 31,642 reads from nine individuals, four control volunteers undergoing routine colonoscopy and five patients undergoing surgical colectomy for medically-refractory UC. Samples were retrieved at four colorectal locations, incorporating the luminal microbiota, mucus gel layer and whole mucosal biopsies.

RESULTS

Interpersonal variability accounted for approximately half of the total variance. Surprisingly, within individuals, asymmetric Eigenvector map analysis demonstrated differentiation between the luminal and mucus gel microbiota, in both controls and UC, with no differentiation between colorectal regions. At a taxonomic level, differentiation was evident between both cohorts, as well as between the luminal and mucosal compartments, with a small group of taxa uniquely discriminating the luminal and mucosal microbiota in colitis. There was no correlation between regional inflammation and a breakdown in this spatial differentiation or bacterial diversity.

CONCLUSIONS

Our study demonstrates a conserved spatial structure to the colonic microbiota, differentiating the luminal and mucosal communities, within the context of marked interpersonal variability. While elements of this structure overlap between UC and control volunteers, there are differences between the two groups, both in terms of the overall taxonomic composition and how spatial structure is ascribable to distinct taxa.

Does conurbation affect the risk of poor mental health? A population based record linkage study

To determine if urban residence is associated with an increased risk of anxiety/depression independent of psychosocial stressors, concentrated disadvantage or selective migration between urban and rural areas, this population wide record-linkage study utilised data on receipt of prescription medication linked to area level indicators of conurbation and disadvantage. An urban/rural gradient in anxiolytic and antidepressant use was evident that was independent of variation in population composition. This gradient was most pronounced amongst disadvantaged areas. Migration into increasingly urban areas increased the likelihood of medication. These results suggest increasing conurbation is deleterious to mental health, especially amongst residents of deprived areas.

Total daily fluoride intake and the relative contributions of foods, drinks and toothpaste by 3- to 4-year-old children in the Gaza Strip - Palestine

BACKGROUND

Children in Gaza Strip suffer from a high prevalence of dental fluorosis.

AIMS

To estimate and compare total daily fluoride (F) intake (TDFI) and investigate the relative contributions of different sources of F to TDFI, in 3- to 4-year-old children in Gaza Strip, exposed to low (<0.7 mg/litre), moderate (0.7-1.2 mg/litre) or high (>1.2 mg/litre) F concentrations in tap water.

DESIGN

A 3-day food diary and samples of tap water, drinks, foods, toothpastes and toothbrushing expectorate were collected from 216 children receiving low (n = 81), moderate (n = 72) or high (n = 63) F concentrations in tap water. F concentration of samples was analysed using an F-ion-selective electrode. TDFI from all sources was estimated. Data were analysed by anova and Tukey's test.

RESULTS

The mean (±SD) F concentration in low, moderate and high F tap waters was 0.21(±0.15), 0.91(±0.13) and 1.71(±0.35) mg/litre, respectively. Mean (±SD) TDFI was 0.02(±0.01), 0.04(±0.01) and 0.05(±0.03) mg/kg bw/day, respectively (P < 0.0001). Foods made the largest contribution (63.9%) to TDFI.

CONCLUSION

Total daily fluoride (F) intake increased as F concentration in tap water increased. Foods were the primary source of F. Programmes for monitoring fluoride expose should consider the fluoride concentration of water used for food preparation and local dietary behaviours.