Familial Mesial Temporal Lobe Epilepsy: Clinical Spectrum and Genetic Evidence for a Polygenic Architecture

OBJECTIVE

Familial mesial temporal lobe epilepsy (FMTLE) is an important focal epilepsy syndrome; its molecular genetic basis is unknown. Clinical descriptions of FMTLE vary between a mild syndrome with prominent déjà vu to a more severe phenotype with febrile seizures and hippocampal sclerosis. We aimed to refine the phenotype of FMTLE by analyzing a large cohort of patients and asked whether common risk variants for focal epilepsy and/or febrile seizures, measured by polygenic risk scores (PRS), are enriched in individuals with FMTLE.

METHODS

We studied 134 families with ≥ 2 first or second-degree relatives with temporal lobe epilepsy, with clear mesial ictal semiology required in at least one individual. PRS were calculated for 227 FMTLE cases, 124 unaffected relatives, and 16,077 population controls.

RESULTS

The age of patients with FMTLE onset ranged from 2.5 to 70 years (median = 18, interquartile range = 13-28 years). The most common focal seizure symptom was déjà vu (62% of cases), followed by epigastric rising sensation (34%), and fear or anxiety (22%). The clinical spectrum included rare cases with drug-resistance and/or hippocampal sclerosis. FMTLE cases had a higher mean focal epilepsy PRS than population controls (odds ratio = 1.24, 95% confidence interval = 1.06, 1.46, p = 0.007); in contrast, no enrichment for the febrile seizure PRS was observed.

INTERPRETATION

FMTLE is a generally mild drug-responsive syndrome with déjà vu being the commonest symptom. In contrast to dominant monogenic focal epilepsy syndromes, our molecular data support a polygenic basis for FMTLE. Furthermore, the PRS data suggest that sub-genome-wide significant focal epilepsy genome-wide association study single nucleotide polymorphisms are important risk variants for FMTLE. ANN NEUROL 2023;94:825-835.

Increased paternal corticosterone exposure influences offspring behaviour and expression of urinary pheromones

BACKGROUND

Studies have shown that paternal stress prior to conception can influence the innate behaviours of their offspring. The evolutionary impacts of such intergenerational effects are therefore of considerable interest. Our group previously showed in a model of daily stress that glucocorticoid treatment of adult male mouse breeders prior to conception leads to increased anxiety-related behaviours in male offspring. Here, we aimed to understand the transgenerational effects of paternal stress exposure on the social behaviour of progeny and its potential influence on reproductive success.

RESULTS

We assessed social parameters including social reward, male attractiveness and social dominance, in the offspring (F1) and grand-offspring (F2). We report that paternal corticosterone treatment was associated with increased display of subordination towards other male mice. Those mice were unexpectedly more attractive to female mice while expressing reduced levels of the key rodent pheromone Darcin, contrary to its conventional role in driving female attraction. We investigated the epigenetic regulation of major urinary protein (Mup) expression by performing the first Oxford Nanopore direct methylation of sperm DNA in a mouse model of stress, but found no differences in Mup genes that could be attributed to corticosterone-treatment. Furthermore, no overt differences of the prefrontal cortex transcriptome were found in F1 offspring, implying that peripheral mechanisms are likely contributing to the phenotypic differences. Interestingly, no phenotypic differences were observed in the F2 grand-offspring.

CONCLUSIONS

Overall, our findings highlight the potential of moderate paternal stress to affect intergenerational (mal)adaptive responses, informing future studies of adaptiveness in rodents, humans and other species.

Common risk variants for epilepsy are enriched in families previously targeted for rare monogenic variant discovery

BACKGROUND

The epilepsies are highly heritable conditions that commonly follow complex inheritance. While monogenic causes have been identified in rare familial epilepsies, most familial epilepsies remain unsolved. We aimed to determine (1) whether common genetic variation contributes to familial epilepsy risk, and (2) whether that genetic risk is enriched in familial compared with non-familial (sporadic) epilepsies.

METHODS

Using common variants derived from the largest epilepsy genome-wide association study, we calculated polygenic risk scores (PRS) for patients with familial epilepsy (n = 1,818 from 1,181 families), their unaffected relatives (n = 771), sporadic patients (n = 1,182), and population controls (n = 15,929). We also calculated separate PRS for genetic generalised epilepsy (GGE) and focal epilepsy. Statistical analyses used mixed-effects regression models to account for familial relatedness, sex, and ancestry.

FINDINGS

Patients with familial epilepsies had higher epilepsy PRS compared to population controls (OR 1·20, p_adj = 5×10^-9), sporadic patients (OR 1·11, p_adj = 0.008), and their own unaffected relatives (OR 1·12, p_adj = 0.01). The top 1% of the PRS distribution was enriched 3.8-fold for individuals with familial epilepsy when compared to the lowest decile (p_adj = 5×10^-11). Familial PRS enrichment was consistent across epilepsy type; overall, polygenic risk was greatest for the GGE clinical group. There was no significant PRS difference in familial cases with established rare variant genetic etiologies compared to unsolved familial cases.

INTERPRETATION

The aggregate effects of common genetic variants, measured as polygenic risk scores, play an important role in explaining why some families develop epilepsy, why specific family members are affected while their relatives are not, and why families manifest specific epilepsy types. Polygenic risk contributes to the complex inheritance of the epilepsies, including in individuals with a known genetic etiology.

FUNDING

National Health and Medical Research Council of Australia, National Institutes of Health, American Academy of Neurology, Thomas B and Jeannette E Laws McCabe Fund, Mirowski Family Foundation.

Identification of a recurrent mosaic KRAS variant in brain tissue from an individual with nevus sebaceous syndrome

Nevus sebaceous syndrome (NSS) is a rare, multisystem neurocutaneous disorder, characterized by a congenital nevus, and may include brain malformations such as hemimegalencephaly or focal cortical dysplasia, ocular, and skeletal features. It has been associated with several eponyms including Schimmelpenning and Jadassohn. The isolated skin lesion, nevus sebaceous, is associated with postzygotic variants in HRAS or KRAS in all individuals studied. The RAS proteins encode a family of GTPases that form part of the RAS/MAPK signaling pathway, which is critical for cell cycle regulation and differentiation during development. We studied an individual with nevus sebaceous syndrome with an extensive nevus sebaceous, epilepsy, intellectual disability, and hippocampal sclerosis without pathological evidence of a brain malformation. We used high-depth gene panel sequencing and droplet digital polymerase chain reaction (PCR) to detect and quantify RAS/MAPK gene variants in nevus sebaceous and temporal lobe tissue collected during plastic and epilepsy surgery, respectively. A mosaic KRAS c.34G > T; p.(Gly12Cys) variant, also known as G12C, was detected in nevus sebaceous tissue at 25% variant allele fraction (VAF), at the residue most commonly substituted in KRAS. Targeted droplet digital PCR validated the variant and quantified the mosaicism in other tissues. The variant was detected at 33% in temporal lobe tissue but was absent from blood and healthy skin. We provide molecular confirmation of the clinical diagnosis of NSS. Our data extends the histopathological spectrum of KRAS G12C mosaicism beyond nevus sebaceous to involve brain tissue and, more specifically, hippocampal sclerosis.

Association of SLC32A1 Missense Variants With Genetic Epilepsy With Febrile Seizures Plus

OBJECTIVE

To identify the causative gene in a large unsolved family with genetic epilepsy with febrile seizures plus (GEFS+), we sequenced the genomes of family members, and then determined the contribution of the identified gene to the pathogenicity of epilepsies by examining sequencing data from 2,772 additional patients.

METHODS

We performed whole genome sequencing of 3 members of a GEFS+ family. Subsequently, whole exome sequencing data from 1,165 patients with epilepsy from the Epi4K dataset and 1,329 Australian patients with epilepsy from the Epi25 dataset were interrogated. Targeted resequencing was performed on 278 patients with febrile seizures or GEFS+ phenotypes. Variants were validated and familial segregation examined by Sanger sequencing.

RESULTS

Eight previously unreported missense variants were identified in SLC32A1, coding for the vesicular inhibitory amino acid cotransporter VGAT. Two variants cosegregated with the phenotype in 2 large GEFS+ families containing 8 and 10 affected individuals, respectively. Six further variants were identified in smaller families with GEFS+ or idiopathic generalized epilepsy (IGE).

CONCLUSION

Missense variants in SLC32A1 cause GEFS+ and IGE. These variants are predicted to alter γ-aminobutyric acid (GABA) transport into synaptic vesicles, leading to altered neuronal inhibition. Examination of further epilepsy cohorts will determine the full genotype-phenotype spectrum associated with SLC32A1 variants.

Interventions to reduce socio-economic inequalities in dental service utilisation - a systematic review

OBJECTIVE

A gradient exists where people with lower socio-economic status (SES) use dental services less regularly than others. Evidence suggests these SES differences may contribute to inequalities in oral health. A variety of approaches have been tried to increase regular dental service use, although it is possible that some are ineffective or may even widen SES inequalities. We aimed to undertake a systematic review of interventions to reduce SES differences in dental visiting.

BASIC RESEARCH DESIGN

Interventions limited to those influencing dental service use by adults. Any type of experimental design, investigating interventions aiming to reduce SES inequalities in dental service use, was included. Primary outcome was a measure of dental utilisation.

RESULTS

Electronic search of 8 databases, with citation snowballing, identified 14,396 titles and abstracts. Paper eligibility screening identified 63 full papers, of which 6 met the inclusion criteria. All included studies were conducted in the United States. Of these, three were targeted to parents, and two towards pregnant women. Two studies incorporated mailing postcards as (at least) one component of the intervention, although results were mixed. Another three studies included scheduling dental appointments as part of a multi-component approach, again with mixed results. The remaining study, involving community health advisors undertaking activities aimed at raising community awareness, found no significant intervention effect.

CONCLUSIONS

Evidence in this area is limited and results are mixed. More work is needed to investigate the effectiveness of interventions to reduce SES inequalities, especially in different healthcare systems and involving a wider participant range.

A systematic review of interventions using cue-automaticity to improve the uptake of preventive healthcare in adults: applications to dental visiting

OBJECTIVE

Since behaviour is underpinned by both cognitive and automatic processes, psychological interventions aiming to instigate or modify habitual behaviour (cue-automaticity interventions) offer an alternative to the more commonly used (mainly educational) strategies to increase preventive healthcare use. Theory suggests that low socio-economic (SES) groups are especially likely to benefit. Cue-automaticity describes how repetition of behaviour, initiated by a particular 'cue', in a constant context, leads to the automatic instigation and/or execution of behaviour. Our primary objective was to assess the effectiveness of cue-automaticity interventions to improve the uptake of adult preventive healthcare, and to consider how this might be applied to the design of interventions to promote preventive dental visiting.

BASIC RESEARCH DESIGN

An electronic search, with citation snowballing, of cue-automaticity interventions to influence adult preventive healthcare use was undertaken.

RESULTS

Searching identified 11,888 titles and abstracts. Paper screening left 26 papers, of which 6 RCTs met the inclusion criteria. All 6 incorporated an Implementation Intention (I-I) component. Four studies involved cancer screening and 2 involved vaccination programmes. Five studies showed a significantly positive increase in preventive healthcare use, while one did not.

CONCLUSIONS

Whilst few studies using cue-automaticity to underpin the promotion of preventive care use have been undertaken, studies that do exist have promising results. As cue-automaticity interventions may be of particular benefit to low SES groups, research is needed to investigate whether cue-automaticity interventions can translate into reducing inequalities in attendance for dental check-ups.

The use of diet diaries in general dental practice in England

Objectives

Diet diaries are recommended as a tool to support behaviour change in dental patients at high risk of dental diseases. However, little is known about their use in dental practice. This study aimed to investigate whether and how general dental practitioners (GDPs) use diet diaries and identify factors which influence their use.

Methods

A postal questionnaire was sent to a stratified random sample of general dental practitioners. The questionnaire asked about demographic and professional characteristics of the GDPs and their practices regarding diet advice, collection of dietary information, diet diaries usage (e.g. frequency, considerations and barriers), and interpretation of diet diaries. Descriptive, bivariate and multivariate analyses were conducted.

Results

From 972 eligible GDP participants, 250 (26%) responses were received. Whilst almost all of these GDPs reported giving diet advice to patients routinely, and 40% reported also referring to dental care professionals in the practice to deliver dietary advice, only 28% (70) reported that they are involved in using diet diaries. GDPs appeared to target patients for dietary advice: GDPs reported they personally gave diet advice to an estimated 63% of their patients, and referred patients to DCPs for diet advice for 11% of their (GDPs') patients. GDPs used diet diaries more often for child than adult patients. Diet diaries usage was lower among younger dentists and in practices with higher percentages of NHS patients (p⟨0.05). Perceived insufficient remuneration for time involved in using diet diaries was the main reason given for their lack of use.

Conclusion

Although recommended as best practice, most English GDPs do not frequently use diet diaries to collect diet information in dental practice, mainly due to perceived financial and time constraints. Development of a more efficient tool to assess the dietary habits of dental patients is needed.

The development and psychometric properties of the Arabic version of the child oral health impact profile-short form (COHIP- SF 19)

Background

This study aims to cross-culturally adapt the original English-language COHIP-SF 19 to Arabic culture and to test its psychometric properties in a community sample.

Methods

The Arabic COHIP-SF 19 was developed and its psychometric properties were examined in a population-based sample of 876 schoolchildren who were aged 12 years of age, in Benghazi, Libya. The Arabic COHIP-SF 19 was tested for its internal consistency, reproducibility, construct validity, factorial validity and floor as well as ceiling effects. A Mann-Whitney U test was used to compare the mean scores of COHIP-SF 19 by participants’ caries status and self-reported oral health rating, satisfaction and treatment need.

Results

The Arabic COHIP-SF 19 was successfully and smoothly developed. It showed an acceptable level of equivalence to the original version. Overall, the internal consistency and reproducibility were acceptable to excellent, with a Cronbach’s alpha of 0.84 and an intra-class correlation coefficient (ICC) of 0.76. All hypotheses predefined to test construct validity were confirmed. That is, children who had active dental caries, and who rated their oral health as poor, were not satisfied with their oral health or indicated the need of treatment had lower COHIP-SF 19 scores (P < 0.05). Floor or ceiling effects were not observed. The exploratory Factorial analysis suggested a 4-component solution and deletion of one item.

Conclusion

The Arabic COHIP-SF 19 was successfully developed. The measure demonstrated satisfactory reliability and validity to estimate OHRQoL in a representative sample of 12-year-old schoolchildren.

Do 'poor areas' get the services they deserve? The role of dental services in structural inequalities in oral health

All over the world, we see that communities with the greatest dental need receive the poorest care--a truism first summarised by the Inverse Care Law in 1971. Despite efforts to attract dentists to under-served areas with incentives such as 'deprivation payments', the playing field is still uphill because of the fundamental inequalities which exist in society itself Deep-seated cultural values which are accepting of a power difference between the 'haves' and 'have nots', and that emphasise individualism over collectivism, are hard to shift. The marketization of health care contributes, by reinforcing these values through the commodification of care, which stresses efficiency and the transactional aspects of service provision. In response, practitioners working in deprived areas develop 'scripts' of routines that deliver 'satisfactory care', which are in accord with the wishes of patients who place little value on oral health but which also maintain the viability of the practice as a business. A compliance framework contrasting types of organisational (dental practice) power (coercive, utilitarian, normative) with types of patient orientation (alienative, calculative, moral) identifies where certain combinations 'work' (e.g. normative power--moral orientation), but where others struggle. Thus institutional structures combine with patients' and the wider community's demands, to generate a model of dental care which leaves little scope for ongoing, preventive dental treatment. This means that in poor areas, all too often, not only is less care available, it is of lower quality too--just where it is needed most.

Operationalisation of the construct of access to dental care: a position paper and proposed conceptual definitions

BACKGROUND

'Access' is a term readily used in a political and policy context, but one which has not leant itself to measurement of progress towards policy goals or comparisons between health systems. Like 'quality', 'access' is a multi-dimensional construct, but currently often remains a vague and abstract concept which is difficult to translate into something specific, concrete and therefore measureable.

METHODS

The paper describes previous work and identifies a need for a greater consensus and conceptual clarity in the selection of metrics for dental access.

RESULTS

The construct of dental access is described as involving the concepts of 1: opportunity for access; 2, realised access (utilisation); 3, equity and 4, outcomes. Proposed conceptual definitions are given and a case made for measuring 'initial utilisation' separately from 'continued utilisation', reflecting modern approaches which distinguish 'entry access' (gaining entry to the dental care system), from the process of gaining access to higher levels of care. Using a distinction between 'entry access' and 'effective access' allows a choice of whether to restrict measurement to mainly supply side considerations, or alternatively to extend the measurement to include whether there is equity in the proportion of patients who are able obtain effective needed interventions.

CONCLUSIONS

A development of conceptual definitions of dental access could facilitate measurement of progress towards policy goals and operationalisation of the construct.

The use of conversation mapping to frame key perceptual issues facing the general dental practice system in England

OBJECTIVE

To demonstrate the use of a novel qualitative methodology namely conversation mapping, which can be used to capture differences in stakeholder perspectives and give a root definition of the problem in a complex policy area. The methodology is used in the context of the changes introduced in the English general dental practice system in April 2006, to investigate the key issues facing the system, as perceived by general dental practitioners (GDPs).

BASIC RESEARCH DESIGN

From a broad trigger statement, three transformational statements were produced. Each participant recorded their contribution on a hard diagrammatic form as a 'map', with others responding with their own written comment, thus generating three conversation maps. Thematic analysis resulted in the generation of a preliminary model summarising key perceptual issues.

RESULTS

The five emergent themes identified were: financing, dentists' wants/needs, the role of the public and patients, system goals and policy level decision making. Financing was identified as the core category to which all other categories were related.

CONCLUSIONS

Conversation mapping, a methodology arising from a systems approach, can be used to develop a 'rich picture' of an oral health care system in order to define the core problem within this policy area. Findings suggest that GDPs identify the financing of the system as a fundamental source of problems within the general dental practice system. This appears to be at variance with the perception of policy makers, who report a more limited view, identifying the system of remuneration as the 'heart of the problem'.

Measurement of attitudes of U.K. dental practitioners to core job constructs

OBJECTIVES

To develop a measure to identify dental practitioner attitudes towards core job dimensions relating to job satisfaction and motivation and to test this against practice characteristics and provider attributes of U.K. practitioners.

RESEARCH DESIGN

an 83-item questionnaire was developed from open-ended interviews with practitioners and use of items in previously used dentist job satisfaction questionnaires. This was subsequently sent to 684 practitioners. Item analysis reduced the item pool to 40 items and factor analysis (PCA) was undertaken.

RESULTS

440 (64%) dentists responded. Factor analysis resulted in six factors being identified as distinguishable job dimensions, overall Cronbach's alpha = 0.88. The factors were: 'restriction in being able to provide quality care (F1)', 'respect from being a dentist (F2)', 'control of work (F3)', 'running a practice (F4)', 'clinical skills (F5)', and 'caring for patients (F6)'. All six factors were correlated with a global job satisfaction score, although F1 was most strongly related (r = 0.60). Regression model analysis revealed that 'whether the dentist worked within the National Health Service or wholly or partly in the private sector' (p < 0.001), 'time since qualification' (p = 0.009), and the position of the dentist within the practice (whether a practice owner or associate dentist), (p = 0.047) were predictive of this factor.

CONCLUSIONS

Six core job constructs of U.K. practitioners have been identified, together with several practice characteristics and practitioner attributes which predict these factors. The study demonstrates the importance of refining measures of dentists' job satisfaction to take account of the culture and the system in which the practitioner works.

An investigation of the relationship between untreated decayed teeth and dental sepsis in 5-year-old children

OBJECTIVES

To investigate the prevalence of dental sepsis in 5-year-old children in Scotland and the relationship between sepsis, treated and untreated decayed teeth, oral cleanliness (visible plaque on anterior teeth) and socio-economic deprivation.

SUBJECTS AND METHODS

Six thousand, nine hundred and ninety-four children of mean age 5.3 years were examined as part of a survey conducted under the Scottish Health Board's Dental Epidemiological Programme. The presence of dental sepsis was recorded, in addition to caries status, and presence of plaque. Postal code information was used to obtain a measure of material deprivation. Relationships between sepsis and its possible contributory factors were explored using stepwise logistic regression.

MAIN RESULTS

In the whole sample, 4.8% of children examined had dental sepsis, ranging from 2% in the most affluent areas to 11% in the most deprived. Children with sepsis had much higher caries experience (mean dmft 6.30) than those without sepsis (mean dmft 2.36). However, when these factors and the presence of plaque were entered into a logistic regression model to predict presence or absence of dental sepsis, the most important factor was not deprivation, but untreated decay.

CONCLUSIONS

The proportion of children with sepsis increases markedly with caries experience. This disadvantage can be mitigated if more of the caries experience is treated. These findings would not support a policy of non-intervention for deciduous caries if oral sepsis is to be minimised.

Recording and understanding social histories by dental undergraduates in a community-based clinical programme

Although social inequalities are known to account for large differences in dental health, attitudes to dental attendance and the type of treatment received by the patient, the taking of a patient's social history receives little emphasis in dental undergraduate teaching. Social history is defined as recording the social and family circumstances of the patient. An exercise undertaken by undergraduate dental students on clinical placements in the Community Dental Service (CDS) is described. Students write a profile of the community in which the clinic is situated, write case histories for two of their patients and then highlight issues illustrated by the case histories with reference to information on the wider community and published literature on inequalities in health and barriers to care. Students completing the exercise in April 2000 and their tutors were given additional information, including a checklist to help in the completion of the social histories of the two patients. A comparison with the reports submitted in the previous year showed that this significantly improved the recording and understanding of social history. This exercise provides a means whereby dental public health issues can be taught to undergraduates whilst maintaining relevance to the clinical setting.

General dental practitioner advice regarding the use of fluoride toothpaste in two areas with a school-based milk fluoridation programme and one without such a programme

OBJECTIVE

To describe the knowledge and practice of general denta practitioners (GDPs) working in Liverpool (where there is no milk fluoridation programme) and St Helens and Knowsley, and the Wirral (where children have fluoridated milk in schools and pre-schools) relating to the advice given for child patients regarding the use of fluoridated toothpaste.

DESIGN

Data were collected via a postal questionnaire sent to all 329 GDPs working within the three areas. GDPs working in more than one of the areas and those working in specialist orthodontic or oral surgery practices were excluded.

RESULTS

Two hundred and thirty-four (71%) questionnaires were completed and returned. Only 3% of dentists said that no-one in their practice gave advice on the concentration of fluoride toothpaste to be used. For caries free children under 7 years of age only 64% of GDPs gave advice concerning the concentration of toothpaste which coincided with the available clinical guidelines. Twenty eight per cent of GDPs also contradicted the guidelines by advising children under 7 with high caries to use a low fluoride toothpaste. Although 59% of GDPs in the fluoridated milk areas asked the child whether they had fluoridated milk at school, they did not appear to alter the advice given regarding the use of fluoridated toothpaste.

CONCLUSION

The study showed that a significant number of GDPs did not adhere to clinical guidelines relating to the use of fluoride toothpaste when giving advice to their child patients. For evidence-based dentistry to become a reality in this area, ways must be found to disseminate the available guidelines more fully and increase their acceptance and use by practitioners.

Clinical record keeping by general dental practitioners piloting the Denplan 'Excel' accreditation programme

BACKGROUND

Denplan is a private capitation-based system of providing primary dental care in the UK. An additional programme called Denplan Excel has been developed which requires General Dental Practitioners to instigate various quality processes within their practices in order to become accredited. Clinical record keeping is one area where standards are monitored. This study reports changes in record keeping at patient recall appointments following the implementation of the Denplan Excel programme.

METHOD

Fifty dentists participating in the Denplan Excel pilot programme from different areas of the UK were sampled by means of cluster sampling. Twenty records for each dentist were sampled and items recorded for patients recalled both pre- and post-pilot were compared.

RESULTS

The majority of dentists recorded presenting complaint, diagnosis and treatment plan both pre- and post-pilot. However, post-pilot there were a number of improvements in record keeping. Caries recorded on a grid increased from 7% of records to 46%, basic periodontal examination increased from 48% to 85% of records and the updating of medical history increased from 51% to 65% of records. These findings were all significant at the p<0.01 level.

CONCLUSION

Changes can be achieved by voluntary participation in a system of structured record keeping.

The development and use of a triage protocol for patients with dental problems contacting an out-of-hours general medical practitioner cooperative

PURPOSE OF THE STUDY

The number of patients contacting general medical practitioner (GMP) out-of-hours services with dental problems is perceived to be a significant problem by the medical profession. This study was undertaken to design and pilot a triage protocol that could be used by non-dental staff to refer callers with dental complaints for appropriate treatment.

BASIC PROCEDURES

A triage protocol was designed to address the patient conditions considered to be relevant to emergency dental care. The triage protocol was piloted for three months at a GMP cooperative in North Wales, which provided an out-of-hours service for 61 GMPs. Baseline data were collected for three months prior to the introduction of the triage protocol.

MAIN FINDINGS

The study showed that the number of dental callers contacting the out-of-hours service was not as great as GMPs imagined, and was similar to other studies. The introduction of the triage protocol resulted in a rise in the number of callers asked to call the general dental practitioner (GDP) support line. The number of unregistered patients given the name of a dentist also increased. The need to make a second telephone call seemed not to affect patient satisfaction since when patients were later questioned on their experience, those who had used the service since the introduction of the triage protocol were more likely to be satisfied with the service.

PRINCIPAL CONCLUSIONS

This study provides some evidence that a triage protocol can be used successfully by non-dental staff to sift requests for out-of-hours emergency dental care.

The role of team dentistry in improving access to dental care in the UK

The role of professionals complementary to dentistry (PCDs) in improving access to NHS primary dental care is discussed. The pattern of under-supply of dentists in poor socio-economic areas is highlighted and identified, in drawing a parallel to the workings of primary medical teams, as a possible area where PCDs could be used.

The stereochemistry of desaturations of long-chain fatty acids in Chlorella vulgaris

1. A study was made of the stereospecificity of hydrogen removal in the sequential desaturations performed by intact cells of Chlorella vulgaris in the biosynthesis of oleic acid, linoleic acid and alpha-linolenic acid. 2. By use of erythro- and threo-9,10-(2)H(2)-, -12,13-(2)H(2)- and -15,16-(2)H(2)-labelled precursors, it was demonstrated that the pair of hydrogen atoms removed from each of these positions had the cis relative configuration. 3. That the hydrogen atoms removed in oleic acid and linoleic acid formation were of the d absolute configuration was proved by use of d- and l-9-(3)H-and -12-(3)H-labelled precursors. 4. The presence of a substantial kinetic isotope effect of deuterium at both positions of the putative double bond was indicated, suggesting that the mechanism of desaturation involves simultaneous concerted removal of the pair of hydrogen atoms.