The ethics of consent in delirium studies

BACKGROUND

Delirium is a syndrome of acute, fluctuating confusion, which affects older people who are unwell. Although common and associated with significant poor outcomes, little is known about its pathophysiology, prevention, or treatment. Delirium research could potentially deliver important benefits for patients and is urgently required. However, such research is challenging as it inevitably involves the recruitment of patients who have impaired capacity to consent, due to the nature of delirium itself and the fact that it is people with dementia or severe illness who are most at risk.

AIM

This article explores the ethical tensions inherent in the need to protect vulnerable participants in delirium research and the urgent need for high-quality research in a neglected condition.

CONCLUSIONS

The current research regulations are unnecessarily stringent and may impede good-quality delirium research. There is in particular the danger that they lead to the recruitment of unrepresentative study populations. We suggest a number of changes to the regulations, such as extending the use of the existing European Union procedures for registered medical practitioner proxy consent. We invite comments and feedback from the research community.

The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

Aesthetically objectionable fluorosis in the United Kingdom

OBJECTIVES

A cross-sectional national survey to explore perceptions of dental fluorosis and to determine the proportion of people regarding fluorosis as aesthetically objectionable at differing levels of defect.

METHODS

A survey using a multistage stratified random probability sample of 6,000 UK adult households. Face-to-face interviews were carried out using a structured questionnaire and photographs of different levels of dental fluorosis. Respondents were interviewed about the parameters of satisfaction, attractiveness and need for treatment for dental fluorosis.

RESULTS

The proportion of respondents perceiving teeth as unattractive, unsatisfactory and requiring treatment increased with increasing severity of dental fluorosis. Using agreement between the three negative perceptions as a measure, 14% of the sample perceived mild dental fluorosis as aesthetically objectionable, 45% at moderate level and 91% at severe levels.

CONCLUSION

Negative perceptions of dental fluorosis were lower than reported previously. Three parameters were included in the approach to estimate aesthetically objectionable fluorosis which may provide a more realistic measure than those used previously. The nature of the index and the sample included suggest that findings of this survey provide a reasonable indicator of the likely impact of water fluoridation. Findings may have important implications for fluoridation policies in the United Kingdom and elsewhere.

Prevalence of self-assessed tooth discolouration in the United Kingdom

AIMS

To determine the prevalence of perceived tooth discolouration in the United Kingdom and to investigate socio-demographic variations and satisfaction with own tooth colour.

METHODS

A national cross-sectional questionnaire study was carried out using a multistage random probability sample. Assessment of people's perceptions of their own tooth colour was conducted by asking study participants to match colour to the closest of a set of photocards demonstrating different levels of tooth discolouration. A separate question asked how satisfied they were with their tooth colour. Information on socio-demographic characteristics of the population were gathered at the same time.

ANALYSIS

Data was coded and entered into SPSS software. Descriptive statistics were used to determine the prevalence of perceived discolouration and satisfaction with own tooth colour. Bivariate and regression analyses were performed to explore the effect of socio-demographic variations.

RESULTS

The self-assessment exercise was completed for 3215 subjects. Half of the study population perceived their tooth colour to be normal and 6% perceived that they had severe discolouration, the remainder reported themselves to have levels of tooth discolouration between these two extremes. Satisfaction with tooth colour decreased with increased discolouration. Sex, age, income and smoking, had statistically significant effects on the prevalence of perceived discolouration (P< 0.01).

CONCLUSIONS

Half of the people in this study perceived themselves to have tooth discolouration. Results suggest that the general public is concerned about dental appearance in terms of tooth colour, indicated by public dissatisfaction with relatively mildly discoloured teeth. Findings may suggest that a further increase in the demand of tooth whitening services and cosmetic dentistry in general is likely. The changing emphasis and level of perceived dissatisfaction need to be taken into account in planning dental services. Evidence based approaches are needed for the appropriate management of patients who demand treatment of mild discolouration.

Dopamine receptor subtype density as a function of age in Aplysia californica

The age-associated changes in dopamine subtype receptors were examined in Aplysia californica. The density of the subtype receptors D1, D2, D3 and D4 was examined in the ganglia from 4.5-, 6-, 8-, 9- and 12-month animals. Receptor analysis was performed by examining the binding of radiolabeled ligands to the individual subtypes. [3H]SCH23390 and [3H]Clozapine were used to analyze D1 and D4 specific binding. [3H]Quinpirole was used for determining D2 and D3 specific binding. Specific binding was found to be present for all four receptor subtypes. All receptor subtypes showed an increase in density from 4.5 to 6 months. From 6 to 8 months D2 and D3 decreased, while D1 and D4 increased. D4 showed the strongest increase. All four subtypes examined showed decreases from 8 to 12 months. ANOVA results indicated age was a significant factor in the subtype receptor density for all receptor types.

Caries experience and oral health behavior in Chinese children with cleft lip and/or palate

PURPOSE

The aims of this study were to investigate whether there were different caries levels in 3- to 6-year-old Chinese children who had a cleft lip compared to those with a cleft lip/palate. The goal also was to evaluate parental attitudes toward the feeding habits and oral health care for their children.

METHODS

A cross-sectional study was carried out through a dental examination of a sample of children and a questionnaire to their parents. A sample of 104 3- to 6-year-old children (66 boys and 38 girls) with cleft lip, cleft palate or both were selected from those receiving pre-surgical treatment. Each child was examined and a short questionnaire was given to parents of the children. The form included questions about infant feeding practices, frequency consumption of specific drinks and, children's toothbrushing frequency.

RESULTS

One hundred and four children were examined. Seventy-five percent had some caries experience and rampant caries was present in 26%. Children with cleft palate had a higher prevalence of rampant caries (30%) compared to those with cleft lip (12%). A multivariate analysis yielded feeding practices and mother's education as the variables significantly associated with caries and rampant caries.

CONCLUSIONS

The results of this study show that: 1. Children with a cleft lip/palate have higher levels of dental caries compared to those with a cleft lip alone; 2. The two most important factors for dental caries were: a. whether the child had been bottle-fed and; b. the educational attainment level of the mother.

Effect of early exposure on the integration of dental implants: Part 2--Clinical findings at 6 months postloading

Implant exposure during initial healing after placement has been considered important in both implant integration and postloading effects. This study evaluated the effect of early implant exposure on the clinical findings prerestoration and 6 months postrestoration. Forty-eight implants (24 CPTi and 24 Ti-13-13) were placed in maxillary and mandibular posterior sites in six baboons. Implant exposure was evaluated for 24 of the submerged implants at placement and at each weekly visit for 3 weeks after implant placement. The crestal bone level at maxillary posterior sites was measured at 6-month uncovering, and mandibular sites were measured at 3-month uncovering. All sites were again measured 6 months after restoration placement. Periotest readings were recorded at implant uncovering and again 6 months postloading. Arbitrary groupings of the Periotest values were assigned as good = -7 to -1; guarded = 0 to +2; and poor = +3 to +27. At 6 months postloading, there were no statistical differences between CPTi and Ti-13-13 for change in crestal bone height in either arch. The mean change in maxillary crestal bone height varied from a 0.59- to 1.35-mm loss. The differences between the mean exposed and nonexposed changes were not statistically significant The mean change in mandibular crestal bone height varied from a 0.25- to 0.88-mm loss. Changes in crestal bone height for nonexposed sites from 3-month implant uncovering to 6 months postloading were statistically significant at the mesial, buccal, and lingual aspects. The mean change for the nonexposed distal aspect approached significance. The differences between the mean exposed and nonexposed changes were not statistically significant. The overall percentage of maxillary implants in the good category for nonexposed sites decreased by 41% from uncovering to 6 months after loading, while no change occurred for exposed sites; the percentage of implants in the good category was comparable for early exposed and nonexposed sites (57% and 59%, respectively). At 6 months after loading, the percentage of implants in the good category was more favorable for early exposed (88%) than nonexposed sites (50%). A one-stage implant approach should provide similar postloading clinical results as the two-stage surgical approach.

Oral health status of heroin users in a rehabilitation centre in Hubei province, China

OBJECTIVE

To report on the oral health of heroin users and to determine risk factors for oral health status.

DESIGN

All heroin users at one rehabilitation camp received an interview using a pre-tested questionnaire from one of three trained interviewers and a dental examination using World Health Organization recommended procedures from one of three calibrated dentists.

SETTING

Interviews and examinations were carried out at Hubei Province camp.

PARTICIPANTS

All 520 resident heroin users at the camp participated in the study.

OUTCOME MEASURES

Oral hygiene expressed using the Debris Index; caries status by DMFT; periodontal status by percentage with bleeding, pocketing and calculus; mucosal status using standard World Health Organization criteria.

RESULTS

One hundred (19%) of the heroin users were caries free; their mean DMFT was 4.2. The majority (92%) of the DMFT was decay and only a small proportion (8%) was treatment related. The proportion of heroin users with bleeding, calculus, shallow pocketing and deep pocketing was 42%, 95%, 42% and 8% respectively. The mean Debris Index score was 3.2. Mucosal lesions were present in 31 subjects (6%). Using multivariate analysis, duration of heroin use and education were risk factors for DMFT, route of drug administration was a risk factor for calculus and gender was a risk factor for deep pocketing.

CONCLUSIONS

There are indications of poorer periodontal health as well as higher caries experience in this group when compared to provincial dental epidemiological data. Mucosal lesions were not widely prevalent. Both social factors and characteristics of drug use were related to oral health in this group.

Caries patterns and their relationship to infant feeding and socio-economic status in 2-4-year-old Chinese children

AIMS

To describe the prevalence, severity and patterns of caries in 2-4-year-old children and to evaluate the association between caries experience of the children and their feeding patterns and socio-economic background in terms of mothers' education and family income.

DESIGN

Cross-sectional survey.

SETTING

Suburban area of Hanchuan in Hubei province, China.

PARTICIPANTS

A sample of 426 children (250 boys and 176 girls).

METHODS

Dental-examinations were undertaken in kindergartens using World Health Organization diagnostic criteria for dental caries. Mothers completed a short questionnaire.

OUTCOME MEASURES

Prevalence of caries; rampant caries; caries in incisors; caries in incisors and/or canines and molars; mean number of decayed, missing and filled teeth/surfaces (dmft/s).

RESULTS

36% of the children had caries, 7% had rampant caries. The more extensive pattern of caries involving primary molars as well as incisors and/or canines was seen in 12% of children. Children who had been wholly bottle-fed had five times the risk of having rampant caries compared to children who were breast-fed.

CONCLUSIONS

The results indicated that infant feeding practice might be a key risk factor for the development of caries at an early age in this country as elsewhere.