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Biomedical subjects

Adrian Davis

Publications and source records attributed to Adrian Davis.

13 recordsLinked to original sources
PubMed2006

Sexual dimorphism in immune response genes as a function of puberty.

BACKGROUND: Autoimmune diseases are more prevalent in females than in males, whereas males have higher mortality associated with infectious diseases. To increase our understanding of this sexual dimorphism in the immune system, we sought to identify and characterize inherent differences in immune response programs in the spleens of male and female mice before, during and after puberty. RESULTS: After the onset of puberty, female mice showed a higher expression of adaptive immune response genes, while males had a higher expression of innate immune genes. This result suggested a requirement for sex hormones. Using in vivo and in vitro assays in normal and mutant mouse strains, we found that reverse signaling through FasL was directly influenced by estrogen, with downstream consequences of increased CD8+ T cell-derived B cell help (via cytokines) and enhanced immunoglobulin production. CONCLUSION: These results demonstrate that sexual dimorphism in innate and adaptive immune genes is dependent on puberty. This study also revealed that estrogen influences immunoglobulin levels in post-pubertal female mice via the Fas-FasL pathway.

Animals↗
PubMed2005

The prevalence of ear, nose and throat problems in the community: results from a national cross-sectional postal survey in Scotland.

OBJECTIVE: To assess the prevalence of ear, nose and throat (ENT) symptoms experienced by individuals living in Scotland, and their use of GP or hospital services for these problems. METHODS: A cross-sectional postal self-completed questionnaire was sent to a random sample of 12,100 households throughout Scotland. 15,788 individuals aged 14+ years living in the 7244 households who returned the questionnaire (adjusted response rate 64.2%) participated in the study. RESULTS: Roughly a fifth of respondents reported currently having hearing difficulties, including difficulty following conversations when there is background noise and hearing problems causing worry or upset; few wore a hearing aid regularly. A fifth reported noises in head or ears (tinnitus) lasting more than five minutes. In the previous year, between 13 and 18% of respondents reported persistent nasal symptoms or hayfever, 7% sneezing or voice problems and 31% had at least one episode of severe sore throat or tonsillitis. Nearly 21% of all respondents reported ever having had dizziness in which things seemed to spin around the individual; 29% unsteadiness, light-headedness or feeling faint; 13% dizziness in which the respondent seemed to move. Important gender, age, occupation and deprivation differences existed in the occurrence of these ENT symptoms. There was considerable variation in the proportion of individuals consulting their GP or being referred to hospital for different problems. CONCLUSIONS: ENT problems occur frequently in the community, and most are managed without consulting medical services. Whilst reasonable for many problems, there are likely to be important groups in the community with ENT problems that might benefit from modern interventions.

Adolescent↗
PubMed2005

Screening for hearing loss in childhood: issues, evidence and current approaches in the UK.

Until recently, screening for childhood hearing loss in the UK was based on two universal (i.e. whole population) screens: the infant distraction test screen at age eight months and the school entry hearing screen at age four to five years. Evidence reviewed in the 1990s indicated that the infant distraction test screen was seriously underperforming, but that (based on technology that had become available in the 1980s and 1990s) universal newborn hearing screening could be efficacious. At the same time, evidence was emerging on the importance and value of very early identification and intervention for permanent congenital childhood hearing loss. This led to the decision to implement a national newborn hearing screening programme (NHSP) in England and to phase out the distraction test at eight months. The initial implementation of the programme will be completed in 2005, and we summarize the evidence on the effectiveness of the first phase of the programme here. A number of important issues concerning childhood hearing loss and its management remain unresolved: the burden of late-onset and temporary childhood hearing losses, the most effective approaches to intervention and management, the case for screening for mild and/or unilateral hearing loss, and the role of the School entry screen. Some of the current research efforts to address these are outlined.

Audiology↗
PubMed2004

The epidemiology of hearing problems: how should we investigate it?

Within published reports, the prevalence of reported hearing difficulties is quite variable. In the present study, we have considered factors that could influence the apparent prevalence of hearing difficulties in the Welsh population, surveyed in a number of different studies. The first important factor to emerge was whether the questions were asked in the context of a general health approach (together with questions about other aspects of health), in which case the prevalence was usually less than 15%. When the same questions were posed in conjunction with a number of other questions on auditory function the prevalence was 20% or greater. Secondly, when a household survey approach is used, with one person being asked to respond on behalf of all members of the household, the prevalence among those reporting is markedly higher than among the other members of the household whose problems they are reporting.

Adult↗
PubMed2004

Improving health sector travel.

Preventing ill health and obesity and building more physical activity into our daily lives have never been so high on the agenda, and the way we travel can help. Many workplaces and schools are drawing up travel plans, with the aims usually to minimise car use and encourage healthier and more environmentally friendly travel. The Transport White Paper of 1998 advocated travel plans and singled out hospitals for action. Travel plans continue to be a focus within the latest Transport White Paper, launched in July 2004. This article covers various prompts to the health sector to implement travel plans. It addresses issues and concerns facing NHS Trusts, the practical things Trusts can do, and the increasing amount of good practice available. Finally, it demonstrates that travel plans can work, and are working, in the health sector.

Health Care Sector↗
PubMed2003

The newborn hearing screening programme in England.

Following a systematic review of the role of neonatal hearing screening in the identification of hearing impaired and deaf children in 1997, the Department of Health in England commissioned a national programme of newborn hearing screening in 2001 and has linked a systematic evaluation to the first 23 sites in the implementation of that policy. It is anticipated that all areas of England will participate in the programme by 2004/2005. It is expected that other regions of the UK will also aim for implementation by this date. In addition to successful advocacy by the two major consumer organisations, there were three key elements linked to the decision to implement newborn hearing screening which were primarily evidence based and also driven by two significant service developments. The evidence base showed that newborn hearing screen was considerably more effective and efficient than the infant distraction test used in many areas and that there was a high probability that early intervention increased the potential for better language and communication. The concern over raised anxiety for those parents whose babies need differential assessment as a result of the screen is reduced by the low number of referrals and increased efficiency of assessment when national protocols are used for screening and assessment. The introduction of family friendly hearing services (FFHS) provides a context in which the health, education, voluntary and social services can work together to provide an equitable and seamless service throughout the year for hearing impaired and deaf children and their families. Currently, 22 areas with 110,000 births per annum, have been selected for implementation, some of whom use a pilot community-based model for screening. A major barrier to rapid progress has been a lack of evidence concerning elements of the screening process, e.g. equipment, IT systems, training at all levels. It is anticipated that a further 20-40 areas with an additional 150,000 birth per annum will be brought into the programme by end of 2002/2003. The aims, protocols, training programme and evaluation of the NHS Newborn Hearing Screening Programme are presented with a view to highlighting the research needed to improve specification of large scale screening programmes.

England↗
PubMed2003

Population study of the ability to benefit from amplification and the provision of a hearing aid in 55-74-year-old first-time hearing aid users.

About 40% of 55-74-year-olds have an impairment in at least one ear of 25+ dB HL, and 27% have bilateral impairment at this level, with 11% being impaired bilaterally at 35+ dB HL. Only 6% currently use a hearing aid. The performance of a random sample of participants aged 55-74 years on speech-in-noise tasks shows that significant statistical benefit was obtained from bilateral amplification in over 20% of the population who do not currently use a hearing aid. The offer of a hearing aid to all those who exceeded a 25 dB HL criterion in the worse car was accepted and taken up by 40%, with 16% declining and the remainder being excluded for pathological and logistic reasons (e.g. hearing loss profile not suitable for aid). This is a very high rate of 71% acceptance. One in four fitted with the hearing aid showed a statistical advantage for hearing speech in noise in freefield (noise and speech from in front) with the hearing aid. Thus at least 10% of the population who do not currently use an aid would benefit substantially from a hearing aid in a quiet speech-in-noise environment. Those with poorer cognitive function show greater benefit overall and less disadvantage in very bad signal-to-noise environments. The overall pattern of results support screening and providing hearing aids to those who do not currently have an aid(s), and suggests that there would be considerable population benefit. At least two main questions for further research remain: (1) would bilateral aiding strategies give greater benefit; and (2) would different hearing aids and fitting strategies be more appropriate for people with differing 'cognitive task' loadings on phonological memory and lexical decision factors?

Aged↗
PubMed2000

The prevalence and type of social noise exposure in young adults in England.

There have been several recent reports on the potential risk to hearing from various types of social noise exposure. However, there are few population-based data to substantiate a case for concern. During the last 10-20 years use of personal cassette players (PCPs) has become very much more prevalent, and sound levels in public nightclubs and discotheques are reported to have increased. This study investigated the prevalence and types of significant social noise exposure in a representative population sample of 356 18-25 year olds in Nottingham. Subjects were interviewed in detail about all types of lifetime noise exposure. Noise measurements were also made for both nightclubs and PCPs. In the present sample, 18.8% of young adults had been exposed to significant noise from social activities, compared with 3.5% from occupational noise and 2.9% from gunfire noise. This indicates that social noise exposure has tripled since the early 1980s in the UK. Most of the present day exposure, measured in terms of sound energy, comes from nightclubs rather than PCPs. Moreover, 66% of subjects attending nightclubs or rock concerts reported temporary effects on their hearing or tinnitus. As will be reported in a later publication, any persistent effect of significant noise exposure on 18-25 year olds is difficult to show, however these data suggest that further work is indicated to study the possibility of sub-clinical damage, and also to consider the implications for employees of nightclubs.

Journal Article↗
PubMedDate not supplied

A questionnaire study of the quality of life and quality of family life of individuals complaining of tinnitus pre- and post-attendance at a tinnitus clinic.

Tinnitus is a condition that is difficult to treat, and treatment outcomes are difficult to measure The majority of people who experience tinnitus are not troubled by it; however, the troubled minority are referred by an otorhinolaryngologist for specialist clinic help. The aim of this study was to investigate how the impact of tinnitus changes following attendance at a tinnitus clinic and to find out how acceptable the questionnaires used were for measuring recovery. Fifty-seven tinnitus sufferers completed three questionnaires covering the characteristics of tinnitus, and its effect on daily life, quality of life, and quality of family life, before and after treatment at the Nottingham Tinnitus Clinic. Questionnaires were answered at patients' homes while they were on the waiting list to attend the clinic, and again I year after their first attendance. Measures of functional and social handicap were significantly reduced following attendance at the clinic (mean change in functional handicap = 13%, p<0.01, and mean change in social handicap = 8%, p<0.01). Quality of life was significantly better after treatment at the clinic (mean visual analog scale difference = 6.5%, p = 0.01). We conclude that attendance at the Nottingham Tinnitus Clinic had a positive effect on the impact of tinnitus on patients and their families, and that the questionnaires gave an accurate measure of patient distress.

Family↗
PubMedDate not supplied

Targeted delivery of salicylic acid from acne treatment products into and through skin: role of solution and ingredient properties and relationships to irritation.

Salicylic acid (SA) is a beta hydroxy acid and has multifunctional uses in the treatment of various diseases in skin such as acne, psoriasis, and photoaging. One problem often cited as associated with salicylic acid is that it can be quite irritating at pH 3-4, where it exhibits the highest activity in the treatment of skin diseases. We have identified strategies to control the irritation potential of salicylic acid formulations and have focused on hydroalcoholic solutions used in acne wipes. One strategy is to control the penetration of SA into the skin. Penetration of the drug into various layers of skin, i.e., epidermis, dermis, and receptor fluid, was measured using a modified Franz in vitro diffusion method after various exposure times up to 24 hours. A polyurethane polymer (polyolprepolymer-15) was found to be an effective agent in controlling delivery of SA. In a dose-dependent fashion it targeted delivery of more SA to the epidermis as compared to penetration through the skin into the receptor fluid. It also reduced the rapid rate of permeation of a large dose of SA through the skin in the first few hours of exposure. A second strategy that proved successful was incorporation of known mild nonionic surfactants like isoceteth-20. These surfactants cleanse the skin, yet due to their inherent mildness (because of their reduced critical micelle concentration and monomer concentration), keep the barrier intact. Also, they reduce the rate of salicylic acid penetration, presumably through micellar entrapment (either in solution or on the skin surface after the alcohol evaporates). Cumulative irritation studies showed that targeting delivery of SA to the epidermis and reducing the rapid early rate of penetration of large amounts of drug through the skin resulted in a reduced irritation potential. In vivo irritation studies also showed that the surfactant system is the most important factor controlling irritancy. SA delivery is secondary, as formulations with less SA content reduced the rate of delivery to the receptor and yet were some of the most irritating formulations tested, presumably due to the action of the specific anionic surfactant on the barrier. Alcohol content also did not appreciably affect irritation and SA delivery; formulations with considerably lower alcohol content but containing anionic versus nonionic surfactant systems exhibited considerably higher irritancy. Thus the surfactant type was again the predominant factor in those studies, although arguably alcohol plays some role (solubilization of SA). Results showed that both polymers and mild surfactants work in concert to provide the optimal formulation benefits of targeted delivery and reduced irritation. Synergistic relationships among hydroalcoholic formulation components will be discussed along with the mechanisms likely involved in controlling delivery of SA to skin.

Acne Vulgaris↗