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Biomedical subjects

D Edwards

Publications and source records attributed to D Edwards.

At least 19 recordsLinked to original sources
PubMed2006

Effects of long-term hormone treatment and of tibolone on monoamines and monoamine metabolites in the brains of ovariectomised, Cynomologous monkeys.

The effects of long-term hormone treatment on monoamines and monoamine metabolites in different regions of the primate brain were examined and compared. Ovariectomised Cynomologous monkeys received daily oral administration of either conjugated equine oestrogens (CEE), CEE + medroxyprogesterone acetate (MPA), or a low or high dose of tibolone, for a period of 2 years. Tissue punches collected from frozen sections through various regions of the forebrain, midbrain, and hindbrain were assayed for levels of dopamine, dihydroxyphenylacetic acid (DOPAC), serotonin, 5-hydroxyindole acetic acid (5-HIAA), and norepinephrine by high-performance liquid chromatography. Few differences between hormone-treated animals and ovariectomised controls were observed. No statistically significant effects of CEE relative to controls were detected in any of the seven brain regions analysed. Animals treated with CEE + MPA showed significant reductions in 5-HIAA in the dorsal raphe nucleus, a significant reduction in dopamine in the hypothalamus, and a significant reduction in serotonin (5-HT) levels in area 8AD of the frontal cortex. Similar to CEE, no significant effects of tibolone relative to controls were detected; however, animals treated with high-dose tibolone showed a decrease in 5-HT levels in the frontal cortex that approached significance and was similar to the effect of CEE + MPA. Collectively, the findings suggest that long-term oral administration of these compounds has relatively few effects on the levels of dopamine, serotonin, and their primary metabolites in the primate brain. This differs from the significant effects on serotonergic and dopaminergic systems detected following parenteral treatment with oestradiol and progesterone, and likely reflects differences between the effects of treating with CEE + MPA versus oestradiol and progesterone on brain monoaminergic systems.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2006

Timing of re-transfusion drain removal following total knee replacement.

INTRODUCTION: The use of postoperative drains following total knee replacement (TKR) has recently been modified by the use of re-transfusion drains. The aim of our study was to investigate the optimal time for removal of re-transfusion drains following TKR. PATIENTS AND METHODS: The medical records of 66 patients who had a TKR performed between October 2003 and October 2004 were reviewed; blood drained before 6 h and the total volume of blood drained was recorded. RESULTS: A total of 56 patients had complete records of postoperative drainage. The mean volume of blood collected in the drain in the first 6 h was 442 ml. The mean total volume of blood in the drain was 595 ml. Therefore, of the blood drained, 78% was available for transfusion. CONCLUSION: Re-transfusion drains should be removed after 6 h, when no further re-transfusion is permissible.

Arthroplasty, Replacement, Knee↗
PubMed2005

The correlation between indices of deprivation and health-related quality of life in patients with oral and oropharyngeal squamous cell carcinoma.

Deprivation influences the incidence and outcome of patients with cancer. Health-related quality of life (HR-QoL) is an important measure of outcome but there is little on this subject and its correlation with deprivation in patients with oral and oropharyngeal cancer. Our aim was to ascertain the extent of deprivation in a cohort of patients who had operations for primary oral and oropharyngeal cancer and how deprivation affected HR-QoL in these patients during and after their treatment. A total of 278 consecutive patients who were operated on for oral and oropharyngeal cancer were included in this study. Validated measures of deprivation scores (Townsend, Carstairs, Jarman and Index of Multiple Deprivation 2000) were calculated, as well as patient-based indicators of social circumstances (marital status, smoking habit, alcohol intake). Comparison was made with the University of Washington-Quality of Life (UW-QoL) scores before and after treatment (6, 12, and 24 months).

Age Factors↗
PubMed2005

[Relative bioavailability of an optimised galenical formulation of mefloquine].

The bioequivalence of an optimised formulation of a generic mefloquine (Mephaquin Lactabs/Test) compared to the reference product under fed conditions was assessed in a GCP/ICH conformable study. A standard two-way randomised crossover design with a 9 week washout period between treatments was used. Blood samples for determination of mefloquine concentrations for calculation of Cmax and AUC were collected at pre-dose and at predefined intervals up to 2016 hours after administration of a single oral dose of 750 mg. A standard bioequivalence analysis was performed on the two one-sided t-test procedure for log-transformed Cmax and AUC. 90% confidence intervals were calculated for both parameters and evaluated against regulatory standards of 80-125% (T/R). Analysis of plasma for mefloquine concentration was performed using a validated LC/MS method with MS detection. The ratio of mean AUC and Cmax (T/R) was 1.015 and 1.044, respectively. The 90% confidence intervals were 95.8-109.3% for AUC and 98.2-110.5% for Cmax. Mephaquin produces plasma concentrations comparable to those after administration of the reference product. The 90% confidence intervals for AUC and Cmax are within the acceptable ranges for bioequivalence of 80-125%. Thus, the optimised galenical formulation of Mephaquin Lactabs is bioequivalent to the reference product.

Administration, Oral↗
PubMed2005

Factors influencing the effectiveness of clinical supervision.

Clinical supervision is widely accepted as an essential prerequisite for high quality nursing care. This paper reports findings from a study that aims to identify the factors that may influence the effectiveness of clinical supervision for community mental health nurses (CMHNs) in Wales, UK. Two hundred and sixty (32%) CMHNs from an estimated total population of 817 completed the Manchester Clinical Supervision Scale (MCCS) and a demographic questionnaire. The MCCS is a 36-item questionnaire measuring the quality and effectiveness of the supervision received. Three-quarters of CMHNs reported having participated in six or more sessions of supervision in their current posts. Clinical supervision was more positively evaluated where sessions lasted for over one hour, and took place on at least a once-monthly basis. Perceived quality of supervision was also higher for those nurses who had chosen their supervisors, and where sessions took place away from the workplace. These findings have important implications for the organization and delivery of mental health nursing services.

Adult↗
PubMed2003

Influence of specialization on the management and outcome of patients with pancreatic cancer.

BACKGROUND: Cancer care is increasingly specialized. Relationships between pancreatic cancer care, mortality and patterns of clinical practice among the full spectrum of patients, including those with irresectable tumours, are not well understood. METHODS: A cohort of 782 patients diagnosed prospectively with pancreatic cancer in 29 acute hospitals in England and Wales over 1 year were followed for 2-3 years. The effects of doctors' and hospitals' specialization, indicated by annual patient volumes, on operative mortality rates, survival times, and test and treatment provision were studied. Multiple logistic and Cox regression models were used to control for prognostic factors and treatments, providing adjusted odds and hazard ratios associated with a higher volume of ten patients annually. RESULTS: Patients managed by higher-volume hospitals survived significantly longer (hazard ratio 0.88 (95 per cent confidence interval (c.i.) 0.83 to 0.93); P < 0.001). They were more likely to undergo cytological examination (odds ratio (OR) 1.21 (95 per cent c.i. 1.01 to 1.35)), resection (OR 1.44 (1.17 to 1.79)) and biliary stenting (OR 1.17 (1.02 to 1.34)), and were less likely to have bypass surgery (OR 0.66 (0.55 to 0.78)). Patients of higher-volume doctors were more likely to undergo endoscopic retrograde cholangiopancreatography (OR 1.59 (1.19 to 2.11)), percutaneous transhepatic cholangiography (OR 1.50 (1.12 to 2.00)), laparoscopy (OR 1.81 (1.07 to 3.06)), resection (OR 1.84 (1.29 to 2.61)) and bypass surgery (1.71 (1.25 to 2.33)). CONCLUSION: Specialization appears to improve survival and to promote more thorough investigation.

Clinical Competence↗
PubMed2003

A systematic review of stress and stress management interventions for mental health nurses.

BACKGROUND: Health care professionals in the United Kingdom (UK) appear to have higher absence and sickness rates than staff in other sectors, and stress may be a reason for nurses leaving their jobs. These problems need to be addressed, particularly in the mental health field, if current service provision is to be maintained. AIM: The aim was to identify stressors, moderators and stress outcomes (i.e. measures included those related to stress, burnout and job satisfaction) for mental health nurses, as these have clear implications for stress management strategies. METHOD: A systematic review of research published in English between 1966 and 2000 and undertaken in the UK that specifically identified participants as mental health nurses was carried out to determine the effectiveness of stress management interventions for those working in mental health nursing. Studies from non-UK countries were examined as potential models of good practice. The study was limited to primary research papers that specifically involved mental health nurses, where the health outcomes measured were stressors, moderators and stress outcomes and where sufficient data was provided. RESULTS: The initial search identified 176 papers, of these 70 met the inclusion criteria. Seven studies have been reported since the completion of the review and have been included in this article. Sixty-nine focused on the stressors, moderators and stress outcomes and eight papers identified stress management techniques. Relaxation techniques, training in behavioural techniques, stress management workshops and training in therapeutic skills were effective stress management techniques for mental health nurses. Methodological flaws however, were detracted from the rigour of many of the studies. CONCLUSIONS: The review demonstrated that a great deal is known about the sources of stress at work, about how to measure it and about the impact on a range of outcome indicators. What was found to be lacking was a translation of these results into practice, into research that assessed the impact of interventions that attempt to moderate, minimize or eliminate some of these stressors.

Adaptation, Psychological↗
PubMed2002

Cohort study in South and West England of the influence of specialization on the management and outcome of patients with oesophageal and gastric cancers.

BACKGROUND: To evaluate specialization in National Health Service (NHS) cancer care, volume-outcome relationships were examined. METHODS: This was a cohort study of 1512 patients with oesophageal or gastric cancer in 23 acute NHS hospitals. Outcomes were survival time and operative (30 day) mortality. Multiple regression analysis was performed, adjusted for diagnoses, prognoses and treatments. RESULTS: For oesophageal cancer, the operative mortality rate decreased by 40 per cent (odds ratio 0.60 (95 per cent confidence interval (c.i.) 0.36 to 0.99 per cent); P = 0.047) for each increase of ten patients in doctors' annual surgical caseloads, and the risk of death decreased by 8 per cent (hazard ratio 0.92 (95 per cent c.i. 0.85 to 0.99); P = 0.021) for each increase of ten patients in doctors' annual caseloads. For gastric cancer, the operative mortality rate decreased by 41 per cent (odds ratio 0.59 (95 per cent c.i. 0.32 to 1.07)) for each increase of ten patients in doctors' annual surgical caseloads, and the risk of death decreased by 7 per cent (hazard ratio 0.93 (95 per cent c.i. 0.89 to 0.98); P = 0.009) for each increase of ten patients in hospitals' annual caseloads. Patients of higher-volume doctors were more likely to receive most investigations and treatments, independently of presenting features. CONCLUSION: The study supports concentration of services for oesophageal and gastric cancers. Specialization of doctors and their teams is at least as important as specialization of hospitals.

Cancer Care Facilities↗
PubMed2002

Amplification and detection of transposon insertion flanking sequences using fluorescent muAFLP.

The amplification of transposon insertionflanking sequences is the basis of a variety of techniques usedfor the detection and characterization of specific transposon insertion events. We have developed a method for the efficient size determination and quantification of amplified genomic sequences thatflank Mutator (Mu) transposon insertions in maize. Using this detection method, we have been able to optimize Mu insertion site amplification and to assess amplification from increasingly complex templates representing increasing numbers of Mu-active maize plants. This detection method should be applicablefor the characterization of transposon or transgene insertion events in a wide variety of organisms.

DNA Primers↗
PubMed2001

T1-T1 interactions occur in ER membranes while nascent Kv peptides are still attached to ribosomes.

For voltage-gated K+ channels (Kv), it is not clear at which stage during biosynthesis in the endoplasmic reticulum (ER) oligomerization occurs, specifically whether it can begin while nascent peptide chains of individual subunits are still attached to ribosomes. Kv channels possess a T1-recognition domain in the NH2-terminus, which confers subfamily specificity for intersubunit assembly and forms a tetramer. Using pairs of cysteines engineered into the T1-T1 interface and cross-linking methods, we show that specific residues in the T1-T1 interface of different Kv1.3 subunits come into close proximity in the ER, both in microsomal membranes and in Xenopus oocytes. Furthermore, using translocation intermediates containing pairs of engineered cysteines in the T1 interface, we demonstrate that specific residues in the folded T1 domain interface can approach within 2 A of each other and form tetramers while the nascent Kv1.3 peptides are still attached to ribosomes and have translocated across the membrane. ER membranes are required for this interaction, and T1-T1 interactions occur inter-polysomally. Thus, folding of the T1 domain and intersubunit interaction may represent the first assembly event in channel formation.

Animals↗
PubMed2001

Specialist practice for UK community mental health nurses: the 1998--99 survey of course leaders.

Surveys of the leaders of the UK's post-qualifying education courses for community mental health nurses have taken place, on an annual basis, for over 10 years. In this paper, findings from the survey undertaken in the 1998--99 academic year are reported. These findings include: that most course leaders do not personally engage in clinical practice; that interprofessional education takes place at a minority of course centres, and that course philosophies and aims are characterised by an emphasis on both outcomes (in terms of, for example, skills acquisition, knowledge development and the ability to engage in reflective practice), and process (adult learning).

Attitude of Health Personnel↗
PubMed2001

Delays in rod-mediated dark adaptation in early age-related maculopathy.

OBJECTIVE: To determine whether there are disturbances in the rod-mediated kinetics of dark adaptation in early age-related maculopathy (ARM). DESIGN: Comparative, observational case series. PARTICIPANTS: Twenty older adults with early ARM as defined by one or more large (> 63 microm) drusen, focal hyperpigmentation, or both, but no choroidal neovascularization or geographic atrophy, and 16 adults in the same age range with none of these fundus features. All participants had 20/25 visual acuity or better in the tested eye. METHODS: Dark adaptation functions were measured using a modified Humphrey Field Analyzer (Zeiss Humphrey Systems, Dublin, CA) to assess the rate of rod-mediated sensitivity recovery at 12 degrees on the vertical meridian in the inferior visual field after exposure to the equivalent of a 98% bleach. Baseline (prebleach) scotopic sensitivity, visual acuity, contrast sensitivity, and photopic sensitivity were also measured. MAIN OUTCOME MEASURES: Rod-cone break; second and third components of rod-mediated dark adaptation; time to baseline sensitivity; and baseline (prebleach) scotopic sensitivity. RESULTS: Although their visual acuity was at least 20/25, patients with early ARM on average exhibited deficits in almost all rod-mediated parameters of dark adaptation as compared with age-similar healthy participants. For example, the rod-cone break was delayed approximately 10 minutes in early ARM patients as compared with healthy participants. Age-related maculopathy patients were more likely to fall outside the normal reference range for variables representing dark adaptation kinetics than for steady-state visual functions such as scotopic sensitivity. For example, 85% of ARM patients fell outside the normal reference range in at least one dark adaptation kinetic parameter, whereas only 25% of ARM patients fell outside the normal reference range for steady-state scotopic sensitivity. CONCLUSIONS: Rod-mediated kinetic parameters of dark adaptation, which reflect the sensitivity recovery of the visual cycle, are disrupted early in ARM pathogenesis.

Aged↗
PubMed2001

A stepwise multivariate analysis of factors that contribute to stress for mental health nurses working in the community.

AIMS: The aim of the study was to examine the variety, frequency and severity of stressors experienced by community mental health nurses (CMHNs) in Wales. BACKGROUND: Numerous studies undertaken throughout the United Kingdom (UK) have indicated that those health professionals working as part of community teams are experiencing increasing levels of stress and burnout. Sample sizes have tended to be small and participants have been drawn mainly from sites in England. METHODS: A questionnaire booklet, which included a number of validated measures, was distributed to 614 CMHNs. These included Maslach Human Services Survey, Community Psychiatric Nursing (CPN) Stress Questionnaire, PsychNurse Coping Questionnaire, Rosenberg Self-Esteem Scale and General Health Questionnaire GHQ-12. The study was the largest of its kind conducted in the UK. RESULTS: Data were collected from 301 CMHNs, representing a response rate of 49%. Community mental health nurses identified the most stressful issues as trying to maintain a good quality service in the midst of long waiting lists and poor resources and having too many interruptions while trying to work in the office. The best demographic predictors of high stress scores were having an unsupportive line manager, working with a specific client group and not having job security. These factors accounted for 20% of the variance in the total stress score. When the results from the psychometric instruments were included, 46% of the variance in the total stress score was accounted for. The predictive variables were emotional exhaustion, working with a specific client group, job security and alcohol consumption. CONCLUSIONS: These findings indicate that there is a need to create more supportive environments both in terms of job security and management support, especially for those working in the fields of severe mental illness and rehabilitation.

Adult↗
PubMed2001

Self-esteem and student nurses: an account of a descriptive study.

In this paper the authors describe a study of nursing students' self-reported self-esteem levels using a validated instrument: the Culture-Free Self-Esteem Inventory 2 (CFSEI-2). The research question was: How do student nurses rate their own self-esteem levels? The paper offers a short review of some of the literature, followed by a description of the sample (a convenience sample of 101 undergraduate nursing students), data collection and analysis methods and the findings. The self-esteem components of CFSEI-2 are general, personal and social and these terms are defined in the text of this paper. The findings indicated that the mean scores for this sample of nursing students fell within normal levels for all three components of self-esteem. Younger students were found to have higher scores for the social subscale, which indicates that they had a higher perception of the quality of their relationships with their peers. The findings of this study indicate that these undergraduate student nurses' perceptions of their self-esteem were comparable to the normal ranges of self-esteem as assessed by the instrument.

Humans↗
PubMed2001

Roots: evolutionary origins and biogeochemical significance.

Roots, as organs distinguishable developmentally and anatomically from shoots (other than by occurrence of stomata and sporangia on above-ground organs), evolved in the sporophytes of at least two distinct lineages of early vascular plants during their initial major radiation on land in Early Devonian times (c. 410-395 million years ago). This was some 15 million years after the appearance of tracheophytes and c. 50 million years after the earliest embryophytes of presumed bryophyte affinity. Both groups are known initially only from spores, but from comparative anatomy of extant bryophytes and later Lower Devonian fossils it is assumed that, during these times, below-ground structures (if any) other than true roots fulfilled the functions of anchorage and of water and nutrient acquisition, despite lacking an endodermis (as do the roots of extant Lycopodium spp.). By 375 million years ago root-like structures penetrated almost a metre into the substratum, greatly increasing the volume of mineral matter subject to weathering by the higher than atmospheric CO(2) levels generated by plant and microbial respiration in material with restricted diffusive contact with the atmosphere. Chemical weathering consumes CO(2) in converting silicates into bicarbonate and Si(OH)(4). The CO(2) consumed in weathering ultimately came from atmospheric CO(2) via photosynthesis and respiration; this use of CO(2) probably accounts for most of the postulated 10-fold decrease in atmospheric CO(2) from 400-350 million years ago, with significant effects on shoot evolution. Subsequent evolution of roots has yielded much-branched axes down to 40 microm diameter, a lower limit set by long-distance transport constraints. Finer structures involved in the uptake of nutrients of low diffusivity in soil evolved at least 400 million years ago as arbuscular mycorrhizas or as evaginations of "roots" ("root hairs").

Biological Evolution↗