O106 Maximising the benefits of bariatric surgery through targeting ghrelin: a randomised, double-blind, placebo-controlled crossover study in people with suboptimal weight loss after bariatric surgery

Introduction

One in 5 people have a suboptimal weight-loss (WL) response to bariatric surgery. The causes are unclear, but patients report resumed hunger and increased food intake, eating behaviours driven by the orexigenic hormone, ghrelin. This proof-of-concept study aimed to evaluate the impact of reducing circulating acyl-ghrelin, the biologically active isoform, on appetite and energy intake in people with suboptimal WL and aberrant ghrelin profile after bariatric surgery.

Methods

Thirty-five patients with <20%WL from 12 months after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) and aberrant circulating ghrelin profile underwent 10 days of treatment with a novel, highly-selective ghrelin o-acyltransferase inhibitor, GLWL-01, and placebo. The primary endpoint was within-person change in ad libitum energy intake during a test meal on day 10. Secondary endpoints assessed subjective appetite, food cravings, macronutrient intake, gut hormones, cardiometabolic profile and body composition. Ethical approval was obtained.

Results

Thirty-one participants (26 RYGB, 9 SG) completed both cycles. GLWL-01 produced a 58.9±27.2% decrease in fasting plasma acyl-ghrelin and 29.3±27.1% increase in desacyl-ghrelin after 10 days. Marked reduction in subjective hunger, food cravings and hedonic influence on appetite was observed with GLWL-01, however objective appetite measures – ad libitum and free-living energy intake – did not change. Circulating levels of cardiovascular risk-conferring lipoproteins significantly improved and no adverse impact on glycaemic control was observed.

Conclusion

Pharmacological modulation of the ghrelin system may be used as part of a personalised therapeutic approach to optimise clinical outcomes in patients with suboptimal WL after bariatric surgery.

Take-home message

This first-in-human mechanistic study shows that pharmacological modulation of the ghrelin system is a promising therapeutic strategy for maximising weight loss response to bariatric surgery.

Thyroid Function and the Risk of Alzheimer's Disease: A Mendelian Randomization Study

Background: Observational studies suggest an association between thyroid function and risk of dementia, but the causality and direction of these effects are unclear. We aim to test whether genetically predicted variation within the normal range of thyroid function and hypothyroidism is causally associated with the risk of Alzheimer's disease (AD). Methods: Mendelian randomization (MR) analyses using genetic instruments are associated with normal range thyrotropin (TSH) and free thyroxine (fT4) levels. Secondary analyses included investigation of the role of hypothyroidism. Bidirectional MR was conducted to address the presence of a potential reverse causal association. Summary statistics were obtained from the ThyroidOmics Consortium involving up to 119,715 individuals and the latest AD genome-wide association study data including up to 71,880 cases. Results: MR analyses show an association between increased genetically predicted normal range TSH levels and a decreased risk of AD (p = 0.02). One standard deviation increased normal range TSH levels were associated with a decreased risk of AD in individuals younger than 50 years old (p = 0.04). There was no evidence for a causal association between fT4 (p = 0.54) and AD. We did not identify any effect of the genetically predicted full range TSH levels (p = 0.06) or hypothyroidism (p = 0.23) with AD. Bidirectional MR did not show any effect of genetic predisposition to AD on TSH or fT4 levels. Conclusions: This MR study shows that increased levels of genetically predicted TSH within the normal range and in younger individuals are associated with a decreased risk of AD. We observed a marginal association between genetically predicted full range TSH and AD risk. There was no evidence for an effect between genetically predicted fT4 or hypothyroidism on AD. Future studies should clarify the underlying pathophysiological mechanisms.

A pilot randomised controlled trial of befriending by volunteers in people with intellectual disability and depressive symptoms

BACKGROUND

People with intellectual disability (ID) are more likely to experience chronic depression compared with the general population, which may be compounded by loneliness and lower levels of social support. Befriending aims to provide social support and promote engagement in community activities. No randomised controlled trials have examined whether befriending improves symptoms of depression and social outcomes in people with ID. The aim of this pilot trial was to assess the feasibility and acceptability of a future larger trial of one-to-one befriending by volunteers in people with ID and depressive symptoms.

METHODS

Participants were adults with mild or moderate ID with a score of 5 or more on the Glasgow Depression Scale for People with Learning Disabilities (GDS-LD). They were randomised to the intervention arm (matched to a volunteer befriender for 6 months) or the control arm (usual care). Volunteers received training and supervision provided by two community befriending schemes. The main outcomes were feasibility of recruitment (minimum target n = 35), retention rate of participants, adherence (minimum 10 meetings), acceptability of the intervention, changes in depressive symptoms (assessed at baseline and 6 months) and feasibility of collecting data for a health economic analysis.

RESULTS

Recruitment was challenging, and only 16 participants with ID and 10 volunteers were recruited. Six participants were matched with a volunteer and no participants dropped out (except for two volunteers). Four participants completed 10 meetings (mean 11.8). Befriending was thought to be acceptable, but modifications were suggested. An exploratory analysis suggested that GDS-LD score was lower in the intervention group compared with the control group after adjusting for baseline scores, but not significant (adjusted mean difference: -4.0; 95% confidence interval: -11.2 to 3.2).

CONCLUSIONS

A large trial would not be feasible based on the recruitment strategies employed in this study. A further feasibility study addressing these challenges or the use of other study designs should be considered.

External validation of the HCM Risk-Kids model for predicting sudden cardiac death in childhood hypertrophic cardiomyopathy

Background

Sudden cardiac death (SCD) is the most common mode of death in childhood hypertrophic cardiomyopathy (HCM). The newly developed HCM Risk-Kids model provides clinicians with individualised estimates of risk. The aim of this study was to externally validate the model in a large independent, multi-centre patient cohort.

Methods

A retrospective, longitudinal cohort of patients diagnosed with HCM aged 1–16 years independent of the HCM-Risk-Kids development and internal validation cohort was studied. Data on HCM Risk-Kids predictor variables (unexplained syncope, non-sustained ventricular tachycardia, maximal left ventricular wall-thickness, left atrial diameter and left ventricular outflow tract gradient) were collected from the time of baseline clinical evaluation. The performance of the HCM Risk-Kids model in predicting risk at 5 years was assessed.

Results

The cohort consisted of 421 patients with a median age at baseline evaluation of 12.3 years (IQR 7.3, 14.4). Over a median total follow up 3.48 years (IQR 1.83, 6.62, range 1 month – 20.7 years). Fourteen patients (3.3%) died and 10 (2.4%) underwent cardiac transplantation. Twenty-three patients (5.4%) met the SCD end-point within 5-years, with an overall incidence rate of 2.03 per 100 patient years (95% CI 1.48–2.78). Model validation showed a Harrell's C-index of 0.745 (95% CI 0.52–0.97) and Uno's C-index 0.714 (95% 0.58–0.85) with a calibration slope of 1.15 (95% 0.51–1.80). Figure 1a describes the agreement between predicted and observed 5-year cumulative proportion of SCD or equivalent events for each tertile of predicted risk in one imputed data set. One hundred and twenty-five (29.7%) patients had a predicted 5-year risk of ≥6%. SCD events occurred in 6 patients (2.0%) with a predicted risk <6% and 17 (13.6%) with a predicted risk ≥6. A 5-year predicted risk threshold of ≥6% identified 17 (73.9%) SCD-events with a corresponding C-statistic of 0.702 (95% CI 0.60–0.81) (Figure 1b).

Conclusions

This study reports the first external validation of the HCM Risk-Kids model in a large and geographically diverse patient population. A 5-year predicted risk of ≥6% identified over 70% of events, confirming that HCM Risk-Kids provides a method for individualised risk predictions and shared decision making in children with HCM. Incorporation of the model into routine clinical care will enable independent prospective model validation and assessment of the effect of its use in clinical practice.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart FoundationMedical Research Council Observed vs predicted risk by tertilesObserved vs predicted by threshold

Improving management of visually impaired patients from occupational therapy perspective: A case report

The ability to detect and recognise visual deficits among visually impaired patients can improve the management of daily living skills and activities of these patients. In this report, the importance of using objective and subjective visual performance measures by occupational therapists in managing visually impaired patients is discussed. We describe a case of a 17-year-old Malay female who had vision impairment due to a cataract, a secondary complication from diabetes mellitus (DM). The Brain Injury Visual Assessment Battery for Adult (biVABA) can provide occupational therapists with additional visual performance information and a better understanding of managing visually impaired patients. The biVABA was used in conjunction with other activities of daily living skills tools such as Modified Barthel Index (MBI), Lawton Instrumental Activities of Daily Living Scale (IADL) and EVS Orientation and Mobility Screening (EVS-O&M) for a more holistic assessment. This approach provides more relevant and essential information in managing visually impaired patient rehabilitation from the occupational therapy perspective.

The relationship between left ventricular outflow tract gradient and sudden cardiac death in childhood hypertrophic cardiomyopathy

Background

The most common mode of death in childhood hypertrophic cardiomyopathy (HCM) is sudden cardiac death (SCD). Left ventricular outflow tract obstruction (LVOTO) is an established risk factor for SCD in adults with the disease. In contrast, the prognostic implications of LVOTO in childhood disease is unclear, with recent studies suggesting that it may have an inverse relationship with the risk of SCD.

Purpose

The aim of this study was to explore the role of LVOTO and the risk of SCD in childhood HCM.

Methods

A multi-centre, retrospective, longitudinal cohort of 871 children (diagnosed with HCM <16 years of age) was used to explore the relationship between SCD and LVOTO (LVOT gradient ≥30mmHg).

Results

189 patients (23%) had LVOTO, which was mild (30–50mmHg), moderate (50–100mmHg) or severe (>100mmHg) in 58 (6.7%), 98 (11.3%) and 33 (3.8%), respectively. The risk of SCD showed an inverse relation to LVOT gradient severity compared to those with no obstruction: mild HR 1.75 (95% CI 0.89–3.44), moderate HR 1.04 (95% 0.55–1.98), and severe HR 0.7 (0.36–1.35) [figure].On univariable analysis [table] LVOTO was associated with heart failure symptoms (NYHA>1) [p <0.001], maximal wall thickness (MWT) [p <0.001], left atrial (LA) diameter [p <0.001], and future myectomy occurring during follow up [p <0.001]. The inverse relationship observed was not altered by the presence or absence of other traditional risk factors.

Conclusions

LVOTO appears to have a complex relationship with the risk of SCD in childhood HCM, with multiple contributing factors. The pathophysiological mechanisms behind this observation need further exploration, which may be limited by low patient numbers

Cummulative incidence of SCD by LVOTO

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): British Heart Foundation

From high to low malaria transmission in Zanzibar-challenges and opportunities to achieve elimination

BACKGROUND

Substantial global progress in the control of malaria in recent years has led to increased commitment to its potential elimination. Whether this is possible in high transmission areas of sub-Saharan Africa remains unclear. Zanzibar represents a unique case study of such attempt, where modern tools and strategies for malaria treatment and vector control have been deployed since 2003.

METHODS

We have studied temporal trends of comprehensive malariometric indices in two districts with over 100,000 inhabitants each. The analyses included triangulation of data from annual community-based cross-sectional surveys, health management information systems, vital registry and entomological sentinel surveys.

RESULTS

The interventions, with sustained high-community uptake, were temporally associated with a major malaria decline, most pronounced between 2004 and 2007 and followed by a sustained state of low transmission. In 2015, the Plasmodium falciparum community prevalence of 0.43% (95% CI 0.23-0.73) by microscopy or rapid diagnostic test represented 96% reduction compared with that in 2003. The P. falciparum and P. malariae prevalence by PCR was 1.8% (95% CI 1.3-2.3), and the annual P. falciparum incidence was estimated to 8 infections including 2.8 clinical episodes per 1000 inhabitants. The total parasite load decreased over 1000-fold (99.9%) between 2003 and 2015. The incidence of symptomatic malaria at health facilities decreased by 94% with a trend towards relatively higher incidence in age groups > 5 years, a more pronounced seasonality and with reported travel history to/from Tanzania mainland as a higher risk factor. All-cause mortality among children < 5 years decreased by 72% between 2002 and 2007 mainly following the introduction of artemisinin-based combination therapies whereas the main reduction in malaria incidence followed upon the vector control interventions from 2006. Human biting rates decreased by 98% with a major shift towards outdoor biting by Anopheles arabiensis.

CONCLUSIONS

Zanzibar provides new evidence of the feasibility of reaching uniquely significant and sustainable malaria reduction (pre-elimination) in a previously high endemic region in sub-Saharan Africa. The data highlight constraints of optimistic prognostic modelling studies. New challenges, mainly with outdoor transmission, a large asymptomatic parasite reservoir and imported infections, require novel tools and reoriented strategies to prevent a rebound effect and achieve elimination.

Determination of the 99th percentile upper reference limit for high-sensitivity cardiac troponin I in Malaysian population

Introduction of high-sensitivity cardiac troponin I (hscTn I) assays for routine clinical use in Malaysia requires determination of the 99^th percentile upper reference limit (URL) for each assay to suit local context. Hence, this study aimed to determine the 99^th percentile URL for hscTn I in the Malaysian population. A total of 250 (120 males and 130 females) healthy Malaysian blood donors aged 18 to 60 years old were recruited. Blood samples for hscTn I were measured using Abbott Diagnostics hscTn I assay on Architect i2000sr analyser. The 99^th percentile was calculated using a non-parametric method and gender specific results were compared. The 99^th percentile URL for hscTn I for the overall population was 23.7 ng/L, with gender specific values being 29.9 ng/L and 18.6 ng/L for male and female, respectively. Females had significantly lower hscTn I compared to males. This study confirms the use of gender specific 99^th percentile URL for hscTn I for clinical use in a multi-ethnic Malaysian population.

Effectiveness and cost-effectiveness of a cardiovascular risk prediction algorithm for people with severe mental illness

Introduction

Cardiovascular risk prediction tools are important for cardiovascular disease (CVD) prevention, however, which algorithms are appropriate for people with severe mental illness (SMI) is unclear.

Objectives/aims

To determine the cost-effectiveness using the net monetary benefit (NMB) approach of two bespoke SMI-specific risk algorithms compared to standard risk algorithms for primary CVD prevention in those with SMI, from an NHS perspective.

Methods

A microsimulation model was populated with 1000 individuals with SMI from The Health Improvement Network Database, aged 30–74 years without CVD. Four cardiovascular risk algorithms were assessed; (1) general population lipid, (2) general population BMI, (3) SMI-specific lipid and (4) SMI-specific BMI, compared against no algorithm. At baseline, each cardiovascular risk algorithm was applied and those high-risk (> 10%) were assumed to be prescribed statin therapy, others received usual care. Individuals entered the model in a ‘healthy’ free of CVD health state and with each year could retain their current health state, have cardiovascular events (non-fatal/fatal) or die from other causes according to transition probabilities.

Results

The SMI-specific BMI and general population lipid algorithms had the highest NMB of the four algorithms resulting in 12 additional QALYs and a cost saving of approximately £37,000 (US$ 58,000) per 1000 patients with SMI over 10 years.

Conclusions

The general population lipid and SMI-specific BMI algorithms performed equally well. The ease and acceptability of use of a SMI-specific BMI algorithm (blood tests not required) makes it an attractive algorithm to implement in clinical settings.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Low vision rehabilitation and ocular problems among industrial workers in a developing country

AIM

Work-related ocular injuries and illnesses were among the major causes of job absenteeism. This study was conducted to determine if low vision rehabilitation was provided following work-related ocular problems among industrial workers in a developing country. This was a retrospective analysis of case records.

METHOD

Randomly selected records of all employees from the Social Security Organization (SOCSO) Medical Board for 2004 who suffered from ocular injuries and illnesses were selected. Rates of ocular injuries and illnesses according to age, gender, races, types of injuries, types of industries, visual rehabilitation and types of medical interventions were tabulated and analysed.

RESULTS

A total of 26 cases of ocular injuries and illnesses were identified where 46.2% suffered from ocular injuries. The remaining 53.8% had ocular and/or systemic diseases. The 40-49-yearold age group suffered the greatest number of injuries (26.92%). Ocular perforating injuries (66.67%) and ocular contusions (33.33%) were the most common types of ocular injury among industrial workers in Kuala Lumpur. Most injuries occurred among workers in the service industry (50%). Almost 60% of these injured workers did not receive any low vision rehabilitation after medical intervention while 25% were given contact lenses or spectacles as rehabilitation and remaining had surgery.

CONCLUSION

The low vision rehabilitation is still unexplored in the management of ocular injuries and illnesses among industrial workers. Introducing low vision rehabilitation can benefit both workers and employers as it provides care beyond spectacles or contact lens prescriptions.

Restorative Treatment Decisions for Deep Proximal Carious Lesions in Primary Molars

AIM

To assess clinicians' individual variables that might influence decision-making for the restoration of deep proximal carious lesions in primary molars.

METHODS

A pre-coded questionnaire that sought participants' treatment choices for a deeply carious second mandibular primary molar, as depicted in a simulated periapical radiograph, along with a specific clinical scenario, was distributed among a random sample of 157 dentists and 15 paediatric dentists. Participants were asked to answer questions. After combining the pulpotomy and pulpectomy treatment choices under a 'pulp therapy' category, a binary dependent variable was constructed. Logistic regression of the ratio of the participants who would restore the questioned tooth by a method in question, was run.

RESULTS

A total of 155 dentists (116 males and 39 females) completed the survey, giving a response rate of 90%. Of these 53% of dentists recommended pulpotomy followed by definitive restoration and 39% recommended removal of caries and restoration without pulp therapy. In the logistic regression model, males and graduates of English language undergraduate dental programs had higher probabilities of restoring without prior pulp therapy (p<0.03 and p<0.02, respectively). Compared with graduates of Asian programs, dentists who graduated from Eastern Europe and the Middle East, showed lower likelihoods of restoring the tooth without prior pulp therapy (p<0.01 and p<0.004, respectively). Dentists who treated an average of 6-16 child patients during a week had a lower probability of restoring the tooth without prior pulp therapy than those who were not currently involved in treating children (p<0.01). No other measured variables were associated with participant's treatment choices.

CONCLUSIONS

The lack of agreement among dentists regarding their optimal treatment recommendations for deep proximal carious lesions appears to be due mainly to inter-individual, educational, training and practice characteristic factors.

Awareness, knowledge and practice of evidence-based dentistry amongst dentists in Kuwait

This study assessed the awareness, knowledge and practice of evidence-based dentistry (EBD) amongst dentists working in the public sector in Kuwait. Of the 150 randomly selected dentists from all five health districts in Kuwait who had originally been approached, 120 participated by completing a pre-tested, self-administered questionnaire (80% response rate). Whereas 60.9% of the group stated that they practice EBD most of the time, fewer (40.8%) had a reasonable understanding of EBD based upon tested knowledge scores of EBD-related topics. Clinical decisions appeared to be mostly based on the clinician's own judgment (73.3%) rather than on evidence-based sources such as PubMed (28.3%) or the Cochrane Library (6.7%). A number of within-group differences were noted, with women (P<0.05), those working in a particular district (P<0.05), those with <10years' experience (P=0.05), those whose first dental qualification had been obtained in Kuwait (P<0.05), and those who had had any EBD training (P<0.05) showing greater knowledge of EBD. Training in EBD was felt necessary by a majority of the group, and this may be facilitated if dental centres have access to evidence-based sources to remove some of the possible barriers to implementation of EBD.

Prosthodontic decision-making: what unprompted information do dentists seek before prescribing treatment?

This study explored the nature of the unprompted information that clinicians seek before making a treatment decision and whether this decision corresponded with the clinical parameters of the case. Interns, general practitioners (GP) and prosthodontists (n = 70, mean age 33 years, range 23-68) were presented with a written vignette of partial edentulism that included two spaces and were invited to ask any questions for the purpose of making a treatment recommendation. A list of 48 potential question/answer items was available to the interviewer, of which 38 were asked. These were then allotted to four thematic categories. Mean number of questions asked did not differ significantly amongst groups, although prosthodontists asked significantly more questions in the 'clinical and radiographic information' category than GPs (P = 0.0001) and interns (P = 0.003). The relationship between a prescribed treatment and questions asked was tested by dichotomizing all recommendations into 'possible' or 'not possible' based on the authors' knowledge of the actual case history. There were no significant differences amongst the groups in the frequency of prescribing 'possible' treatment (Pearson chi-square 0.083 and 0.108 for upper and lower spaces, respectively), but those who prescribed 'possible' treatment asked significantly more questions in the 'clinical and radiographic information' category, specifically about bone adequacy in the edentulous areas: upper jaw (P = 0.0001) and lower jaw (P = 0.003). It may be concluded that prosthodontists generally opted for more 'possible' treatments, as well as seeking items of information that seemed to improve the chance of making recommendations that conformed to the actual case characteristics.

Measuring disease progression in frontotemporal lobar degeneration: a clinical and MRI study

OBJECTIVES

There is currently much interest in biomarkers of disease activity in frontotemporal lobar degeneration (FTLD). We assessed MRI and behavioral measures of progression in a longitudinal FTLD cohort.

METHODS

Thirty-two patients with FTLD (11 behavioral variant frontotemporal dementia [bvFTD], 11 semantic dementia [SemD], 10 progressive nonfluent aphasia [PNFA]) and 24 age-matched healthy controls were assessed using volumetric brain MRI and standard behavioral measures (Mini-Mental State Examination, Frontal Assessment Battery, Clinical Dementia Rating Scale, Neuropsychiatric Inventory with Caregiver Distress scale) at baseline and 1 year later. A semi-automated image registration protocol was used to calculate annualized rates of brain atrophy (brain boundary shift integral [BBSI]) and ventricular expansion (ventricular boundary shift integral [VBSI]). Associations between these rates and changes in behavioral indices were investigated.

RESULTS

Rates of whole brain atrophy were greater in the entire FTLD cohort and in each subgroup compared with controls (all p < or = 0.004). Rates of ventricular expansion were greater in the entire cohort (p < 0.001) and the SemD (p = 0.002) and PNFA (p = 0.05) subgroups compared with controls. Changes in Mini-Mental State Examination, Frontal Assessment Battery, and Clinical Dementia Rating Scale scores were associated with MRI measures of progression, though not uniformly across FTLD subgroups. Both BBSI and VBSI yielded feasible sample size estimates for detecting meaningful treatment effects in SemD and PNFA language subgroups. Sample sizes were substantially larger using MRI biomarkers for the bvFTD subgroup, and using behavioral biomarkers in general.

CONCLUSIONS

Semi-automated MRI atrophy measures are potentially useful objective biomarkers of progression in frontotemporal lobar degeneration (FTLD); however, careful stratification of FTLD subtypes will be important in future clinical trials of disease-modifying therapies.

The future of complete dentures in oral rehabilitation. A critical review

Based on available investigations and current trends in oral rehabilitation published in the dental literature, an attempt is made to describe the possible future role of complete dentures. For edentulous patients, complete dentures have for long been the only prosthodontic treatment option. Whereas a large number of edentulous patients report satisfaction with denture usage, a smaller number are unable to adapt; for such patients, sophistication of clinical and technical processes or quality of denture-supporting tissues, appear to have little influence on patient-perceived outcomes. Since the 1980s, osseointegrated dental implants have dramatically improved the therapeutic possibilities, especially so for maladaptive patients. Those able to access such treatment can expect significant improvements in oral functional status and quality of life. While there is a downward trend in edentulism in several countries, it is region-specific, confirming the overriding influence of socio-economic factors on health status. In most societies, despite ageing populations, the need for complete dentures is not likely to reduce in the near future. Whereas a two- or even a one-implant overdenture for the edentulous mandible is increasingly regarded as a minimum standard of care in many developed countries, its routine prescription for the majority in the world who are disadvantaged is unrealistic; for them, even 'low-tech' therapies like conventional dentures are beyond their reach. Improving the conventional management of edentulous patients is a necessity and requires a keener focus by researchers, educators and clinicians in the developed world on the needs of populations with fewer resources.

Profile of low vision children in the special education schools in Malaysia

This study looked at the causes of vision loss, levels of distance, near vision and the use of low vision devices (LVDs) in children studying at special schools in Malaysia. A total of 139 children from two special education schools took part. Visual acuity was measured with and without LVDs. Those who required further assessment were referred to Low Vision Clinic. Near visual acuity in 71 children ranged from N4 to N64. Sixty eight children could not read the N64 chart or they were totally blind. Only eight students were using LVDs before intervention. Seventy one children were referred for low vision assessment and 48 were found to benefit from the LVDs prescribed. The major cause of visual impairment was cataract (17%). Hand held magnifier was the most preferred LVD. Majority of the children attending the blind schools had residual vision but did not have LVDs. LVDs are able to significantly improve near visual acuity and hence there is a need to prescribe and train the children to use the LVDs.

Rehabilitation of the worn dentition

The purpose of this review was to evaluate the literature on the rehabilitation of tooth wear, with some pertinent historical, epidemiological and aetiological aspects of tooth wear provided as background information. In historical skull material, extensive tooth wear, assumed to be the result of coarser diets, was found even in relatively young individuals. Such wear is seldom seen in current populations. Although many of the factors associated with extensive tooth wear in historical material are no longer present or prevalent, new risk factors have emerged. In the young individual, the literature points to a global rise in soft drink consumption as the most significant factor in the development of tooth wear through dental erosion. Among older individuals, lifestyle changes and chronic diseases that are controlled with medications that may, in turn, result in regurgitation and/or dry mouth, are possible reasons amongst others for the widespread clinical impression of an increasing prevalence of tooth wear. The aetiology of tooth wear is multifactorial and the role of bruxism is not known. Clinical controlled trials of restorative and prosthodontic approaches for the range of clinical conditions that wear can give rise to, are limited in number and quality. Equally, the striking lack of evidence regarding the long-term outcomes of treatment methods and materials calls for caution in clinical decision-making. Notwithstanding these observations, clinicians have provided and continue to provide rehabilitative strategies for managing their patients' worn dentitions that range traditionally from extensive prosthodontics to an increasing reliance on adhesive techniques.

Tracking progression in frontotemporal lobar degeneration: serial MRI in semantic dementia

BACKGROUND

Semantic dementia is a sporadic neurodegenerative disorder characterized by the progressive erosion of semantic processing and is one of the canonical subtypes of frontotemporal lobar degeneration. This study aimed to characterize the pattern of global and regional longitudinal brain atrophy in semantic dementia and to identify imaging biomarkers that could underpin therapeutic trials.

METHODS

Twenty-one patients with semantic dementia (including eight pathologically confirmed cases) underwent whole-brain and region-of-interest analyses on volumetric brain MRI scans at two time points. Sample size estimates for trials were subsequently calculated using these data.

RESULTS

Mean (SD) whole-brain atrophy rate was 39.6 (31.9) mL/y [3.2 (12.0) mL/y in controls], with ventricular enlargement of 8.9 (4.4) mL/y [1.0 (1.0) mL/y in controls]. All patients had a smaller left temporal lobe at baseline [left mean 31.9 (6.9) mL, right mean 49.2 (9.5) mL; p < 0.0001]; however, the mean rate of atrophy was significantly greater in the right temporal lobe [right 3.9 (1.7) mL/y, left 2.8 (1.2) mL/y; p = 0.02]. Similarly, whereas the left hippocampus was smaller at baseline, the mean atrophy rate was significantly greater in the right hippocampus. Using the atrophy rates generated, sample size requirements for clinical trials were found to be smallest for temporal lobe measurement.

CONCLUSIONS

These findings show that the rate of tissue loss in the right temporal lobe overtakes the left temporal lobe as semantic dementia evolves, consistent with the later development of symptoms attributable to right temporal lobe dysfunction. Furthermore, our findings demonstrate that MRI measures of temporal lobe volume loss could provide a feasible and sensitive index of disease progression in semantic dementia.

Ethics review of research: in pursuit of proportionality

The ethics review system of research is now well-established, at least in the developed world, although there are many differences in how countries view it and go about managing it. The UK specifically is now seeking to revise its system by speeding up the process of ethics approval but only for some studies. It is proposed that only those studies which pose "no material ethical issues" should be "fast-tracked". However, it is unclear what this means, who should decide and what should be included in this category. In this paper, we go some way towards answering these questions. While we are certain that the debate is only just beginning, we are equally certain that it will continue to run long after the system has been reformed. To stimulate this conversation and to inform a pilot project of the new system directly, we review two candidates to help give some substance to the notion of "material" ethical issues. Firstly, material could mean a certain type or degree of risk. Second, material could mean how physically invasive the research is. We conclude that there is still much work to be done on making the system of governing health and social care consistent and practicable.

The neuro-behavioural syndrome of brainstem disease

We describe two patients with isolated brainstem lesions who exhibited behavioural and cognitive changes that are commonly associated with frontal lobe pathology, as leading clinical features. These cases illustrate the role of distributed neural networks in cognitive and behavioural processes. The brainstem, frontal-subcortical and limbic systems are extensively and reciprocally linked via neurotransmitter projection pathways. We argue that cognitive and behavioural features in patients with brainstem lesions reflect remote effects of brainstem structures on frontal lobe and limbic regions, as a consequence of disruption to ascending neurotransmitter pathways.

Managing the polymerization shrinkage of resin composite restorations: a review

Polymerization shrinkage (PS) of resin composites almost invariably generates a degree of stress at the tooth/restoration interface. The magnitude of the stresses so produced depends on resin composite composition and its ability to flow before solidification, which is, in turn related to cavity configuration and curing characteristics of the composite. The purpose of the present article is to review the published literature on the management of PS, with special reference to those elements that are under the control of the dentist. Available data from laboratory, finite element analysis and review articles, relating to the methods and techniques that have been proposed for managing the problem of PS, are included. On the basis of the review, it may be concluded that PS has negative effects on the resin composite/tooth interface. The review identifies the preferred handling and/or management techniques that clinicians might employ to reduce the levels of PS that might affect the restorations they place, and consequently reduce its adverse effects.

Self-disclosure of HIV status: perception of malaysian HIV-positive subjects towards attitude of dental personnel in providing oral care

The objective of this study was to assess the perceptions of Malaysian HIV-positive subjects towards the attitude of dental personnel in providing oral care to them. The study design was cross-sectional with the sampling frame comprising of 27 Government Drug Rehabilitation Centres throughout Malaysia. A convenience sample was then taken from 20 centres with the highest enrolment of HIV-positive subjects. A self-administered questionnaire was used to elicit information on the perception of HIV-positive subjects towards the attitude of dental personnel in providing oral care to the patient with HIV-positive. The study sample consisted of 509 HIV-positive individuals with a mean age of 31.3+/-12.9 years old. Of these, only 15.1% attended a dental clinic after confirmation of HIV-positive status. The study demonstrated that 67.5% of the HIV-positive subjects disclosed their status voluntarily to the dentists and majority of the dentists (76.9%) did not show any negative reaction on knowing their HIV positive status. There was also no difference in the attitude of auxiliary staff toward the above disclosure. In conclusion, the study showed that oral health care personnel are more receptive to the HIV-positive subjects receiving dental care and treatment.

An assessment of endodontic re-treatment decision-making in an educational setting

AIM

To test the applicability of Praxis Concept (PC) theory in endodontic re-treatment decision-making amongst dental students of similar backgrounds, but from two dental schools.

METHODOLOGY

A total of 172 students from two dental schools (n = 97 and n = 75) were asked to select their management choices (from five possible options) for each of six variations on quality (by way of adequacy of root filling) and complexity (by way of absence or presence of a post) of a simulated radiograph of an anterior tooth. The six variations each had five possible levels of periapical condition, giving a total of 30 cases for which management choices were sought. Individual re-treatment preference scores (RPS) were obtained, from which school and gender differences were compared by t-test. The association between students' stated re-treatment propensities and the different cases was expressed as odds ratios using unconditional logistic regression analysis.

RESULTS

There were large inter-individual variations in RPS within the cases at both schools. Mean RPS for the group was 0.62 (SD 0.14), and did not differ between the schools (P = 0.44), but was significantly lower for males than females (P = 0.01). For all participants and a given case, if re-treatment was proposed for a particular size of lesion, then all larger lesions for that case were also marked for re-treatment. Presence of a defective root filling or overfilling reflected a greater propensity for re-treatment than when the root filling was adequate, whilst the absence/presence of a post had no clear effect on re-treatment choices.

CONCLUSIONS

The findings support the explanatory potential of PC theory in endodontic re-treatment decision-making in the group investigated, and suggest that factors besides disease status alone, may contribute to the choices that clinicians make.

Reappraising prosthodontic treatment goals for older, partially dentate people: Part I. Traditional management strategy

In conventional terms, prosthodontic treatment becomes necessary when a patient has missing and/or broken-down teeth. Part I of this two-part series of papers reviews the available evidence for a traditional therapeutic model that seeks purposefully to reconstitute lost morphology, with specific reference to older, partially dentate people, at the population level. Furthermore, because anterior and premolar teeth are indispensable to a number of prime oral functions in most societies, the question of need for replacement relates essentially to that of molar teeth. Research findings are presented which cast doubt on many of the assertions made for the mandatory replacement of all posterior teeth. Specifically, there appears to be a lack of compelling evidence that dental arch integrity is a prerequisite for optimal oral health and function, and favours the prognosis of the remaining dentition. Wide variability in the effects of posterior tooth loss on occlusal stability indicates a 'wait-and-see' management approach rather than immediate replacement, while reported chewing sufficiency in people with reduced but well-distributed dentitions, and a lack of association between the level of posterior support and temporomandibular disorders, further undermine the traditional premise for the mandatory replacement of posterior teeth, specifically molars. With the parallel recognition that the assessment of treatment need must take a broader view of peoples' functional concerns arising from their tooth loss, as well as weighing the cost/benefit ratio of treatment, Part II will compare the merits of the traditional model with the documented functional benefits that a more limited, less morphologically-driven approach may have for the growing, older sector of society.

Marginal adaptation of class II resin composite restorations using incremental and bulk placement techniques: an ESEM study

This in vitro study compared marginal gap formation in class II resin composite restorations. Forty caries-free extracted molars were prepared in a standardized manner for class II restoration by one of four methods: bulk- or incrementally-placed light-activated resin composite (Amelogen), and bulk- or incrementally-placed chemically activated composite (Rapidfill). The restored teeth, after finishing and polishing, and thermocycling, were examined using environmental scanning electron microscopy. Marginal gap measurements at predetermined facial and lingual margin sites showed no significant differences between the two sites within any of the groups. Both the light- and the chemically-activated restorations showed no significant differences in mean marginal gap sizes whether they were placed by incremental or bulk techniques. Amelogen restorations placed by both methods had significantly larger margin gaps than those of each of the Rapidfill groups (P<0.05). Thus, although method of placement of a given material had no significant effect on the quality of marginal adaptation, both of the chemically activated resin composite restorations produced significantly smaller marginal gaps than both the bulk- and incrementally-placed light-activated composites.

Validation of four different risk stratification systems in patients undergoing off-pump coronary artery bypass surgery: a UK multicentre analysis of 2223 patients

BACKGROUND

Various risk stratification systems have been developed in coronary artery bypass graft surgery (CABG), based mainly on patients undergoing procedures with cardiopulmonary bypass.

OBJECTIVE

To assess the validity and applicability of the Parsonnet score, the EuroSCORE, the American College of Cardiology/American Heart Association (ACC/AHA) system, and the UK CABG Bayes model in patients undergoing off-pump coronary artery bypass surgery (OPCAB) in the UK.

METHODS

Data on 2223 patients who underwent OPCAB in eight cardiac surgical centres were collected. Predicted mortality risk scores were calculated using the four systems and compared with observed mortality. Calibration was assessed by the Hosmer-Lemeshow (HL) test. Discrimination was assessed using the receiver operating characteristic (ROC) curve area.

RESULTS

30 of 2223 patients (1.3%) died in hospital. For the Parsonnet score the HL test was significant (p < 0.001) and the receiver operating characteristic curve (ROC) area was 0.74. For the EuroSCORE the HL test was also significant (p = 0.008) and the ROC area was 0.75. For the ACC/AHA system the HL test was non-significant (p = 0.7) and the ROC area was 0.75. For the UK CABG Bayes model the HL test was also non-significant (p = 0.3) and the ROC area was 0.81.

CONCLUSIONS

The UK CABG Bayes model is reasonably well calibrated and provides good discrimination when applied to OPCAB patients in the UK. Among the other three systems, the ACC/AHA system is well calibrated but its discrimination power was less than for the UK CABG Bayes model. These data suggest that the UK CABG Bayes model could be an appropriate risk stratification system to use for patients undergoing OPCAB in the UK.

Interaction of cyclic AMP modulating agents with levcromakalim in the relaxation of rat isolated mesenteric artery

The effect of cyclic AMP modulating agents on levcromakalim-induced relaxation was investigated in myograph-mounted rat mesenteric arteries. Forskolin (adenylyl cyclase activator), dibutyryl cyclic AMP (protein kinase A activator) and 5'-N-ethylcarboxamidoadenosine (NECA; adenosine receptor agonist) all potentiated the vasorelaxant effects of levcromakalim. The modulatory and relaxant effects of dibutyryl cyclic AMP, NECA and forskolin were sensitive to the protein kinase A inhibitor, Rp-cAMPS. However, relaxation to these three agents was unaffected by the K(ATP) inhibitor, glibenclamide. Dibutyryl cyclic AMP and NECA also caused levcromakalim to induce relaxation in the sub-nanomolar concentration range, however, this effect was Rp-cAMPS- and glibenclamide-insensitive. These results suggest that cyclic AMP modulating agents modulate K(ATP), even though this channel does not contribute to their relaxant effects.

Incomplete and inaccurate death certification--the impact on research

BACKGROUND

The objectives of this study were (1) to investigate the extent of erroneous and/or omitted information on death certificates of patients-implanted with Bjork-Shiley Convexo-Concave (BSCC) heart valves; (2) to determine whether this information could be associated with a possible under-reporting of acute mechanical failure of this valve.

METHODS

A review was carried out of death certificates and clinical notes for patients implanted in the United Kingdom with BSCC valves. This was a multicentre study (38 hospitals) based at the Cardiothoracic Department, NHLI, Imperial College School of Medicine at Hammersmith Hospital, London. The subjects were 478 patients implanted with a BSCC valve between 1979 and 1986 who died in the following years: 1984, 1987, 1990, 1993 and 1996. The main outcome measures were: (1) percentage of death certificates that record the presence of a valve prosthesis; (2) percentage of death certificates that record the presence of a valve prosthesis for patients who had a post mortem; (3) percentage of death certificates that record inaccurate or incomplete information related to the surgery; (4) percentage of death certificates that do not record a post mortem where one is known to have been performed.

RESULTS

Twenty-one per cent (101/478) of the total number of death certificates record the presence of the valve prosthesis. Thirty-five per cent (43/123) of the death certificates for patients who had a post mortem record the presence of a valve prosthesis. Six per cent (30/478) of death certificates report inaccurate information related to the valve surgery. Twenty-five per cent (118/478) of the total number of death certificates recorded a single cause of death. Twenty-three per cent (110/478) of all death certificates reviewed recorded only the mode of dying. Eight per cent (10/123) of the total number of death certificates for patients who had a post mortem did not record a post mortem.

CONCLUSIONS

The relatively high number of death certificates that do not record the presence of a valve prosthesis and the observed under-reporting of post mortems may lead to inaccurate reporting of the number of BSCC valves that fail. Previous recommendations to improve accuracy in death certification appear to have gone unheeded, and changes in the way certificates are completed for patients with implanted cardiac devices should be considered.

Dental erosion associated with soft-drink consumption in young Saudi men

This study reports on the causative factors of dental erosion in selected high- (n = 19) and low-erosion (n = 19) subgroups of a larger random sample (n = 95) of young male Saudi military inductees. By means of a questionnaire, the role of various possible factors related to oral health in general, and to dental erosion in particular, was assessed for each participant. Clinical examination included recordings of severity of dental erosion and fluorosis, presence of buccal cervical defects and first permanent molar 'cuppings', DMFT and DMFS, visible plaque index, and gingival bleeding index. In addition, bitewing radiographs, study casts, and intraoral color transparencies were obtained for each individual. Logistic regression analysis showed a strong correlation between the presence of dental erosion and a high level of consumption of cola-type soft drinks. Other statistically significant associated factors, although of less predictive strength, were type of cleaning aid and gingival bleeding index. In subgroup comparisons, dental problems (primarily pain), number of buccal cervical defects, and number of missing teeth were significantly greater in the high- than in the low-erosion subgroup.