Biomedical subjects

Peter Lewis

Publications and source records attributed to Peter Lewis.

6 recordsLinked to original sources

PubMed2006

G80A reduced folate carrier SNP influences the absorption and cellular translocation of dietary folate and its association with blood pressure in an elderly population.

The functional consequences of the G80A RFC SNP on the expressed reduced folate carrier protein were evaluated by looking at the relationship between intake of folate, plasma folate and cellular stores of the vitamin. The effect on homocysteine was also examined. Homocysteine is a thiol that is known to be inversely associated with folate, and which is considered to be both thrombo- and athrogenic. At high levels, homocysteine may also interfere with nitric oxide mediated vasodilation, cause oxidative injury to, and proliferation of the vascular endothelium, and alter the elastic properties of the vascular wall, contributing to increased blood pressure. Participants (119; 52 male, 67 female) from a NSW retirement village were assessed. Independent of gender, the assimilation of folate from dietary sources into red cells showed a significant association for GG (r=0.399; p=0.022) and GA (r=0.564; p<0.0001) subjects, but not homozygous recessive (AA) individuals (r=0.223; p=0.236). The same genotype based pattern of significance was shown for the association between dietary folate and plasma folate (GG: r=0.524; p=0.002, GA: r=0.408; p=0.002). No genotype-related pattern of significance was shown for the association between dietary folate and homocysteine. When examined by gender, some differences were apparent; one-way ANOVA showed that genotype influenced diastolic blood pressure in males (p=0.019), while only females showed a significant correlation between dietary folate and blood pressure within specific genotypes (Systolic pressure GA: r=-0.372; p=0.025, carriage of A: r=0.-0.357; p=0.011. Diastolic pressure GA: r=-0.355; p=0.034, carriage of A: r=0.-0.310; p=0.029). The G80A RFC SNP had an impact on the absorption and cellular translocation of dietary folate and its association with blood pressure in an elderly population.

Absorption↗

PubMed2005

The cost-effectiveness of neonatal screening for cystic fibrosis: an analysis of alternative scenarios using a decision model.

BACKGROUND: The use of neonatal screening for cystic fibrosis is widely debated in the United Kingdom and elsewhere, but the evidence available to inform policy is limited. This paper explores the cost-effectiveness of adding screening for cystic fibrosis to an existing routine neonatal screening programme for congenital hypothyroidism and phenylketonuria, under alternative scenarios and assumptions. METHODS: The study is based on a decision model comparing screening to no screening in terms of a number of outcome measures, including diagnosis of cystic fibrosis, life-time treatment costs, life years and QALYs gained. The setting is a hypothetical UK health region without an existing neonatal screening programme for cystic fibrosis. RESULTS: Under initial assumptions, neonatal screening (using an immunoreactive trypsin/DNA two stage screening protocol) costs 5,387 pound sterling per infant diagnosed, or 1.83 pound sterling per infant screened (1998 costs). Neonatal screening for cystic fibrosis produces an incremental cost-effectiveness of 6,864 pound sterling per QALY gained, in our base case scenario (an assumed benefit of a 6 month delay in the emergence of symptoms). A difference of 11 months or more in the emergence of symptoms (and mean survival) means neonatal screening is both less costly and produces better outcomes than no screening. CONCLUSION: Neonatal screening is expensive as a method of diagnosis. Neonatal screening may be a cost-effective intervention if the hypothesised delays in the onset of symptoms are confirmed. Implementing both antenatal and neonatal screening would undermine potential economic benefits, since a reduction in the birth incidence of cystic fibrosis would reduce the cost-effectiveness of neonatal screening.

Journal Article↗

PubMed2005

Understanding intraaortic balloon pumping.

Nurses are accountable for their care. Understanding the physiology and process behind any intervention improves patient care, while also increasing nursing satisfaction and skill and IABP is no exception. An awareness of IABP will facilitate sound nursing care, ensure early identification of possible complications or patient compromise, and lead to patient and relative satisfaction. It will also assist in the transition from caring for a patient whose needs are relatively straightforward, to caring for one subject to this complex medical intervention.

Equipment Design↗

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↗

PubMed2003

Investigating lifestyle factors affecting hearing aid candidature in the elderly.

Within this presentation, the authors consider briefly the published data on the effects of hearing impairment on lifestyle in the elderly, and suggest that the World Health Organization's International Classification of Functioning, Disability and Health (ICF) would provide a framework for standardizing the study of effects of impairments. This is followed by two studies. In the first study, we asked a consecutive sample of elderly patients (hearing aid candidates and users) to list the activities, transactions and interactions in which they participated, and classified these using the ICF. We then took the main categories, and, in a second study, explored how often individuals participated in them, how much difficulty they had because of their hearing loss, and how much they enjoyed them. This highlighted the considerable difficulties that most such individuals experience in common activities and communication situations, and which seem to be little influenced by whether or not they use hearing aids.

Aged↗

PubMed2002

The short form 36 (SF36) in a specialist tinnitus clinic.

Tinnitus is an extremely common condition which is known to have an effect on quality of life. This study reports the health profile of tinnitus sufferers who attend a specialist tinnitus clinic. This cross-sectional study uses the self-report questionnaire SF36. Two hundred consecutive new patients completed the questionnaire as part of their assessment in a specialist tinnitus clinic in Wales. In all eight scales of the SF36 the mean scores were below that of the general population. Compared to a reference population patients referred to a specialist tinnitus clinic show a reduction in their age/sex-adjusted health profile which is comparable to that of people reporting low back pain. The findings also lend weight to the suggestion that tinnitus sufferers may have a general response bias.

Adult↗