78 research outputs found

    Immunocytochemical investigation of caries-induced neural, vascular and leucocyte responses in human primary and permanent tooth pulp.

    Get PDF
    This immunocytochemical study investigated nerve density and morphology, neuropeptide expression, vascular status and leucocyte accumulation within the human tooth pulp. It specifically examined differences between the primary and permanent dentition, and explored the effect of caries on the above parameters. The study also sought to correlate quantitative findings with a reported pain history. Mandibular first permanent molars and second primary molars were obtained from children requiring dental extractions under general anaesthesia. A simple pain history was elicited for each patient. Following exodontia, teeth were split longitudinally, placed in fixative and were categorised as intact, moderately carious or grossly carious. The coronal pulps were removed and serial frozen sections were processed for indirect immunofluorescence. Triple-labelling regimes were employed using combinations of the following antisera: i) protein gene product 9.5 (a general neuronal marker; ii) the neuropeptides calcitonin gene-related peptide, substance P, vasoactive intestinal polypeptide or neuropeptide Y; iii) Ulex europeaus I lectin (a label for vascular endothelium) and iv) leucocyte common antigen (a general leucocyte marker). Image analysis was then used to determine the percentage area of immunostaining for each label within different anatomical regions of the coronal pulp. The findings revealed that there were significant inter-dentition differences for the biological variables under investigation. Essentially, in intact samples, innervation density and neuropeptide expression were greater in permanent teeth but primary tooth pulps were more vascular and contained a greater number of leucocytes. With caries progression, both dentitions demonstrated significant increases in neural density, neuropeptide expression and leucocyte accumulation. However, changes in pulpal vascularity were limited to the pulp hom regions. The only factors found to correlate with the reported pain history were substance P and vasoactive intestinal polypeptide expression. These peptides were significantly upregulated in painful pulpitis. Finally, there was evidence to suggest that changes in neuropeptide expression were associated with changes in vascular status and leucocyte accumulation within the inflamed pulp. In conclusion, this study has established that significant inter-dentition differences exist in pulpal biology. Furthermore, dynamic changes in pulpal neural density and neuropeptide expression seem to occur with caries progression. These findings are likely to have functional importance in terms of pain experience, inflammation and healing, and thus may help to direct the development of novel therapeutic strategies for the compromised dental pulp

    Life-History Evolution in Guppies. VII. The Comparative Ecology of High- and Low-Predation Environments

    Get PDF
    Prior research has demonstrated a strong association between the species of predators that co-occur with guppies and the evolution of guppy life histories. The evolution of these differences in life histories has been attributed to the higher mortality rates experienced by guppies in high-predation environments. Here, we evaluate whether there might be indirect effects of predation on the evolution of life-history patterns and whether there are environmental differences that are correlated with predation. To do so, we quantified features of the physical and chemical environment and the population biology of guppies from seven high-and low-predation localities. We found that high-predation environments tend to be larger streams with higher light levels and higher primary productivity, which should enhance food availability for guppies. We also found that guppy populations from high-predation environments have many more small individuals and fewer large individuals than those from low-predation environments, which is caused by their higher birth rates and death rates. Because of these differences in size distribution, guppies from high-predation environments have only one-fourth of the biomass per unit area, which should also enhance food availability for guppies in these localities. Guppies from high-predation sites allocate more resources to reproduction, grow faster, and attain larger asymptotic sizes, all of which are consistent with higher levels of resource availability. We conclude that guppies from high-predation environments experience higher levels of resource availability in part because of correlated differences in the environment (light levels, primary productivity) and in part as an indirect consequence of predation (death rates and biomass density). These differences in resource availability can, in turn, augment the effect of predator-induced mortality as factors that shape the evolution of guppy life-history patterns. We found no differences in the invertebrate communities from high- and low-predation localities, so we conclude that there do not appear to be multitrophic, indirect effects associated with these differences in predation

    ‘Message to dentist’: Facilitating communication with dentally anxious children

    Get PDF
    Dental anxiety affects children worldwide and can have negative consequences on oral health. This study aimed to evaluate a novel communication aid ‘message to dentist’ (MTD), as part of a wider cognitive behavioural therapy approach to reduce dental anxiety in young patients. Dentally anxious children, aged 9−16 years, were invited to complete the MTD proforma, before and following their course of treatment. They scored how worried they were and their anticipated pain levels on a scale of 1−10 (10 being the worst outcome). They also wrote down their coping plans and post-treatment reflections. One hundred and five children, from a UK general dental practice and a hospital clinic, were included. They had a mean age of 11.6 years, and 65% were female. There was a significant reduction in self-report worry (from 4.9 to 2.1) and anticipated pain (from 5.1 to 2.0) scores (p 0.05, paired t-test). Many children (30%) used listening to music/audiobook as a coping strategy. Thematic analysis revealed concerns around pain, uncertainty, errors and specific procedures. The MTD proforma proved an effective means of facilitating communication between anxious children and the dental team, allowing them to identify their worries and make personalised coping plans

    Sequencing and characterization of the guppy (Poecilia reticulata) transcriptome

    Get PDF
    Background: Next-generation sequencing is providing researchers with a relatively fast and affordable option for developing genomic resources for organisms that are not among the traditional genetic models. Here we present a de novo assembly of the guppy (Poecilia reticulata) transcriptome using 454 sequence reads, and we evaluate potential uses of this transcriptome, including detection of sex-specific transcripts and deployment as a reference for gene expression analysis in guppies and a related species. Guppies have been model organisms in ecology, evolutionary biology, and animal behaviour for over 100 years. An annotated transcriptome and other genomic tools will facilitate understanding the genetic and molecular bases of adaptation and variation in a vertebrate species with a uniquely well known natural history. Results: We generated approximately 336 Mbp of mRNA sequence data from male brain, male body, female brain, and female body. The resulting 1,162,670 reads assembled into 54,921 contigs, creating a reference transcriptome for the guppy with an average read depth of 28×. We annotated nearly 40% of this reference transcriptome by searching protein and gene ontology databases. Using this annotated transcriptome database, we identified candidate genes of interest to the guppy research community, putative single nucleotide polymorphisms (SNPs), and male-specific expressed genes. We also showed that our reference transcriptome can be used for RNA- sequencing-based analysis of differential gene expression. We identified transcripts that, in juveniles, are regulated differently in the presence and absence of an important predator, Rivulus hartii, including two genes implicated in stress response. For each sample in the RNA-seq study, >50% of high-quality reads mapped to unique sequences in the reference database with high confidence. In addition, we evaluated the use of the guppy reference transcriptome for gene expression analyses in a congeneric species, the sailfin molly (Poecilia latipinna). Over 40% of reads from the sailfin molly sample aligned to the guppy transcriptome. Conclusions: We show that next-generation sequencing provided a reliable and broad reference transcriptome. This resource allowed us to identify candidate gene variants, SNPs in coding regions, and sex-specific gene expression, and permitted quantitative analysis of differential gene expression

    Molar incisor hypomineralisation: Teaching and assessment across the undergraduate dental curricula in the UK.

    Get PDF
    No consensus exists on how molar incisor hypomineralisation (MIH) should be covered by the undergraduate dental curricula. To assess the current teaching and assessment of MIH in the UK. A piloted questionnaire regarding the teaching and assessment of MIH was disseminated to paediatric, restorative and orthodontic teaching leads in each UK dental school (n = 16). Data were analysed using descriptive statistics, chi-squared and Kruskal-Wallis tests. Response rates from paediatric, restorative and orthodontic teams were 75% (n = 12), 44% (n = 7) and 54% (n = 8), respectively. Prevention of caries, preformed metal crowns, anterior resin composites and vital bleaching were taught significantly more by paediatric teams (p = .006). Quality of life and resin infiltration were absent from restorative teaching. Orthodontic teaching focussed on the timing of first permanent molar extractions. Paediatric teams were mainly responsible for assessment. Risk factors, differential diagnoses for MIH and defining clinical features were more likely to be assessed by paediatric teams than by others (p = .006). All specialities reported that students were prepared to manage MIH. Molar incisor hypomineralisation is primarily taught and assessed by paediatric teams. No evidence of multidisciplinary or transitional teaching/assessment existed between specialities. Developing robust guidance regarding MIH learning in the UK undergraduate curricula may help improve consistency

    The CALM trial protocol: a randomised controlled trial of a guided self-help cognitive behavioural therapy intervention to reduce dental anxiety in children

    Get PDF
    Background: Globally, around 13% of children experience dental anxiety (DA). This group of patients frequently miss dental appointments, have greater reliance on treatment under general anaesthesia (GA) and have poorer oral health-related quality of life (OHRQoL) than their non-dentally anxious peers. Recently, a low-intensity cognitive behavioural therapy (CBT)-based, self-help approach has been recommended for management of childhood anxiety disorders. A feasibility study conducted in secondary care found this guided self-help CBT resource reduced DA and a randomised controlled trial was recommended. The present study aims to establish the clinical and cost-effectiveness of a guided self-help CBT intervention to reduce DA in children attending primary dental care sites compared to usual care. Methods: This 4-year randomised controlled trial will involve 600 children (aged 9–16 years) and their parent/carers in 30 UK primary dental care sites. At least two dental professionals will participate in each site. They will be assigned, using random allocation, to receive the CBT training and deliver the intervention or to deliver usual care. Children with DA attending these sites, in need of treatment, will be randomly allocated to be treated either by the intervention (CBT) or control (usual care) dental professional. Children will complete questionnaires relating to DA, OHRQoL and HRQoL before treatment, immediately after treatment completion and 12 months post-randomisation. Attendance, need for sedation/GA and costs of the two different approaches will be compared. The primary outcome, DA, will be measured using the Modified Child Dental Anxiety Scale. Scores will be compared between groups using a linear mixed model. Discussion: Treating dentally anxious patients can be challenging and costly. Consequently, these children are frequently referred to specialist services for pharmacological interventions. Longer waiting times and greater travel distances may then compound existing healthcare inequalities. This research will investigate whether the intervention has the potential to reduce DA and improve oral health outcomes in children over their life-course, as well as upskilling primary dental healthcare professionals to better manage this patient group. Trial registration: This clinical trial has been registered with an international registry and has been allocated an International Standard Randomised Controlled Trial Number (ISRCTN27579420)

    Amelogenesis Imperfecta caused by N-Terminal Enamelin Point Mutations in Mice and Men is driven by Endoplasmic Reticulum Stress

    Get PDF
    ‘Amelogenesis imperfecta’ (AI) describes a group of inherited diseases of dental enamel that have major clinical impact. Here, we identify the aetiology driving AI in mice carrying a p.S55I mutation in enamelin; one of the most commonly mutated proteins underlying AI in humans. Our data indicate that the mutation inhibits the ameloblast secretory pathway leading to ER stress and an activated unfolded protein response (UPR). Initially, with the support of the UPR acting in pro-survival mode, Enam(p.S55I) heterozygous mice secreted structurally normal enamel. However, enamel secreted thereafter was structurally abnormal; presumably due to the UPR modulating ameloblast behaviour and function in an attempt to relieve ER stress. Homozygous mutant mice failed to produce enamel. We also identified a novel heterozygous ENAM(p.L31R) mutation causing AI in humans. We hypothesize that ER stress is the aetiological factor in this case of human AI as it shared the characteristic phenotype described above for the Enam(p.S55I) mouse. We previously demonstrated that AI in mice carrying the Amelx(p.Y64H) mutation is a proteinopathy. The current data indicate that AI in Enam(p.S55I) mice is also a proteinopathy, and based on comparative phenotypic analysis, we suggest that human AI resulting from the ENAM(p.L31R) mutation is another proteinopathic disease. Identifying a common aetiology for AI resulting from mutations in two different genes opens the way for developing pharmaceutical interventions designed to relieve ER stress or modulate the UPR during enamel development to ameliorate the clinical phenotype

    Significant benefits of AIP testing and clinical screening in familial isolated and young-onset pituitary tumors

    Get PDF
    Context Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are responsible for a subset of familial isolated pituitary adenoma (FIPA) cases and sporadic pituitary neuroendocrine tumors (PitNETs). Objective To compare prospectively diagnosed AIP mutation-positive (AIPmut) PitNET patients with clinically presenting patients and to compare the clinical characteristics of AIPmut and AIPneg PitNET patients. Design 12-year prospective, observational study. Participants & Setting We studied probands and family members of FIPA kindreds and sporadic patients with disease onset ≤18 years or macroadenomas with onset ≤30 years (n = 1477). This was a collaborative study conducted at referral centers for pituitary diseases. Interventions & Outcome AIP testing and clinical screening for pituitary disease. Comparison of characteristics of prospectively diagnosed (n = 22) vs clinically presenting AIPmut PitNET patients (n = 145), and AIPmut (n = 167) vs AIPneg PitNET patients (n = 1310). Results Prospectively diagnosed AIPmut PitNET patients had smaller lesions with less suprasellar extension or cavernous sinus invasion and required fewer treatments with fewer operations and no radiotherapy compared with clinically presenting cases; there were fewer cases with active disease and hypopituitarism at last follow-up. When comparing AIPmut and AIPneg cases, AIPmut patients were more often males, younger, more often had GH excess, pituitary apoplexy, suprasellar extension, and more patients required multimodal therapy, including radiotherapy. AIPmut patients (n = 136) with GH excess were taller than AIPneg counterparts (n = 650). Conclusions Prospectively diagnosed AIPmut patients show better outcomes than clinically presenting cases, demonstrating the benefits of genetic and clinical screening. AIP-related pituitary disease has a wide spectrum ranging from aggressively growing lesions to stable or indolent disease course

    Development and evaluation of CARIES-QC: a caries-specific measure of quality of life for children.

    Get PDF
    BACKGROUND: Existing paediatric oral health-related quality of life (OHRQoL) measures are generic instruments designed to evaluate a range of oral conditions. It has been found that disease-specific measures may be more adept at detecting subtle changes which occur following treatment of the condition in question. Furthermore, existing self-report OHRQoL measures have not involved children at all stages of development of the measure. The aim of this study was to develop a caries-specific measure of quality of life for children. METHODS: The first stage of the study involved a qualitative enquiry with children, aged 5-16 years, to inform the development of the measure. Children generated the potential items, contributed to item reduction and questionnaire design and participated in the testing of face and content validity. The resulting measure was evaluated in a cross-sectional validation study. Ethical approval was granted for the study. RESULTS: The qualitative study found that children discussed a number of caries-related impacts which affected their daily lives. These were incorporated into a draft measure which was further refined following testing of face and content validity. This resulted in the production of the Caries Impacts and Experiences Questionnaire for Children (CARIES-QC), comprising 16 items and one global question. Two hundred participants with a mean (range) age of 8.1 (5-16) years took part in the further evaluation of CARIES-QC. Four items, which did not fit the Rasch model, were removed from further analysis. The remaining 12 items demonstrated good internal consistency (alpha = 0.9) and the total score showed significant correlations with the number of decayed teeth, presence of pain, pulpal involvement, the Child Perceptions Questionnaire (16-item short form) and the global score (p < 0.01, Spearman's rho). CONCLUSION: In conclusion, children's input allowed the development of a valid and reliable child-centred caries-specific quality of life measure. CARIES-QC can now be used to evaluate which interventions for dental caries are most effective in reducing impacts from the child's perspective
    • …
    corecore