Search PubMed⌕ Search

Biomedical subjects

Richard Gray

Publications and source records attributed to Richard Gray.

34 records · Page 2Linked to original sources
PubMed2003

Active dendrites, potassium channels and synaptic plasticity.

The dendrites of CA1 pyramidal neurons in the hippocampus express numerous types of voltage-gated ion channel, but the distributions or densities of many of these channels are very non-uniform. Sodium channels in the dendrites are responsible for action potential (AP) propagation from the axon into the dendrites (back-propagation); calcium channels are responsible for local changes in dendritic calcium concentrations following back-propagating APs and synaptic potentials; and potassium channels help regulate overall dendritic excitability. Several lines of evidence are presented here to suggest that back-propagating APs, when coincident with excitatory synaptic input, can lead to the induction of either long-term depression (LTD) or long-term potentiation (LTP). The induction of LTD or LTP is correlated with the magnitude of the rise in intracellular calcium. When brief bursts of synaptic potentials are paired with postsynaptic APs in a theta-burst pairing paradigm, the induction of LTP is dependent on the invasion of the AP into the dendritic tree. The amplitude of the AP in the dendrites is dependent, in part, on the activity of a transient, A-type potassium channel that is expressed at high density in the dendrites and correlates with the induction of the LTP. Furthermore, during the expression phase of the LTP, there are local changes in dendritic excitability that may result from modulation of the functioning of this transient potassium channel. The results support the view that the active properties of dendrites play important roles in synaptic integration and synaptic plasticity of these neurons.

Animals↗
PubMed2003

The effect of medication management training on community mental health nurse's clinical skills.

Background. There is evidence that compliance therapy improves treatment adherence and clinical outcomes in patients with schizophrenia. Community Mental Health Nurses (CMHNs) are ideally placed to deliver compliance therapy but require training to develop the necessary clinical skills.Aim. To explore whether a brief medication management training package is effective in developing the compliance therapy skills of CMHNs.Method. The study had a within subjects repeated measures design. A representative sample of 52 CMHNs entered the study. They performed a role-play task pre- and post-training that was videotaped and blind rated by an independent rater using the Cognitive Therapy Scale (CTS). Knowledge was assessed pre- and post-training using a knowledge about medication management questionnaire. Trainees also completed a satisfaction with training questionnaire at the end of the course.Results. Following training there was a statistically significant improvement in mean scores on the primary measure of skills, the CTS (mean pre-training CTS-total score 13.88, mean post-training CTS-total score 31.12; p<0.01). There was also a significant categorical improvement in the number of trainees who demonstrated satisfactory skills. Knowledge about medication management was significantly improved and trainees reported that training was acceptable and relevant to their clinical practice.Conclusions. In this uncontrolled study training improved the medication management skills of CMHNs.

Clinical Competence↗
PubMed2003

Continuing uncertainty about the value of percutaneous revascularization in atherosclerotic renovascular disease: a meta-analysis of randomized trials.

BACKGROUND: To study the effect of revascularization on blood pressure (BP) and serum creatinine (SCr) in patients with atherosclerotic renovascular disease (ARVD). METHODS: Three randomized studies comparing balloon angioplasty (plus medication if necessary) with medical therapy alone in patients with ARVD were identified. In one study, patients were stratified and analysed according to whether they had unilateral or bilateral disease. Therefore, four sets of results were available for inclusion in a meta-analysis comparing BP and SCr at 6 months and changes from baseline. RESULTS: The three trials recruited 210 patients. There was no clear benefit for angioplasty when comparing BP at 6 months. Relative to the medical therapy group, the mean (95% CI) systolic/diastolic BP was 2.9 mmHg (-9.1, 3.4)/0.35 mmHg (-3.6, 2.9) lower in the angioplasty group (P=0.4/0.8). There was, however, some suggestion of benefit for angioplasty when changes in BP were compared. There was a greater reduction in the systolic/diastolic BP in the angioplasty group, with a difference of 6.3 mmHg (-11.7, -0.8)/3.3 mmHg (-6.2, -0.4) in the mean change (P=0.02/0.03). There was some suggestion of benefit for angioplasty in terms of changes in SCr, although this was not significant (P=0.06). CONCLUSIONS: The reported trials have been too small to determine reliably the role of angioplasty in ARVD. Although the combined results of three previous trials exclude the possibility of a large improvement in renal function or hypertension after angioplasty, a moderate but clinically worthwhile benefit cannot be ruled out. Further large-scale randomized evidence is needed.

Angioplasty, Balloon↗
PubMed2003

Clinical interventions for treatment non-adherence in psychosis: meta-analysis.

BACKGROUND: Studies investigating the efficacy of clinical interventions for reducing treatment non-adherence have generated contrasting findings, and treatment non-adherence remains common in clinical practice. AIMS: To systematically review whether there are effective clinical interventions that community psychiatric services can implement to reduce non-adherence. METHOD: Systematic review and meta-regression analysis of randomised controlled trials (RCTs) and controlled clinical trials (CCTs) were used to assess the efficacy of interventions to enhance adherence. RESULTS: We reviewed 24 studies, more than half of which were RCTs. In 14 studies the experimental intervention was an educational programme. Five studies evaluated pre-discharge educational sessions, three studies explored the benefit of psychotherapeutic interventions and two studies looked at the effect of telephone prompts. The overall estimate of the efficacy of these interventions produced an odds ratio of 2.59 (95% CI 2.21-3.03) for dichotomous outcomes, and a standardised mean difference of 0.36 (95% CI 0.06-0.66) for continuous outcomes. CONCLUSIONS: Community psychiatric services can potentially use effective clinical interventions, backed by scientific evidence, for reducing patient non-adherence.

Community Mental Health Services↗
PubMed2002

Continuous versus interrupted perineal repair with standard or rapidly absorbed sutures after spontaneous vaginal birth: a randomised controlled trial.

BACKGROUND: Trauma to the perineum is a serious and frequent problem after childbirth, with about 350000 women each year in the UK needing sutures for perineal injury after spontaneous vaginal delivery, and many millions more worldwide. We compared the continuous technique of perineal repair with the interrupted method, and the more rapidly absorbed polyglactin 910 suture material with the standard polyglactin 910 material. METHODS: 1542 women who had a spontaneous vaginal delivery with a second-degree perineal tear or episiotomy were randomly allocated to either the continuous (n=771) or interrupted (771) suturing method, and to either the more rapidly absorbed polyglactin 910 suture material (772) or standard polyglactin 910 material (770). Primary outcomes were pain 10 days after delivery and superficial dyspareunia 3 months postpartum. Analysis was by intention to treat. FINDINGS: At day 10, three women had dropped out of the study. Significantly fewer women reported pain at 10 days with the continuous technique than with the interrupted method (204/770 [26.5%] vs 338/769 [44.0%], odds ratio 0.47, 95% CI 0.38-0.58, p<0.0001). Occurrence of pain did not differ significantly between groups assigned the more rapidly absorbed material or standard material (256/769 [33.3%] vs 286/770 [37.1%], 0.84, 0.68-1.04, p=0.10). Women reported no difference in superficial dyspareunia at 3 months for the continuous vs the interrupted method (98/581 [16.9%] vs 102/593 [17.2%], 0.98, 0.72-1.33, p=0.88) or the more rapidly absorbed versus standard material (105/586 [17.9%] vs 95/588 [16.2%], 1.13, 0.84-1.54, p=0.42). Suture removal was done less with the more rapidly absorbed material than with standard suture material (22/769 [3%] vs 98/770 [13%], p<0.0001), and with the continuous versus interrupted method (24/770 [3%] vs 96/769 [12%], p<0.0001). INTERPRETATION: A simple and widely practicable continuous repair technique can prevent one woman in six from having pain at 10 days. Also, the more rapidly absorbed polyglactin 910 material obviates need for suture removal up to 3 months postpartum for one in ten women sutured.

Adult↗
PubMed2002

Dissociation of the effects of preload volume and energy content on subjective appetite and food intake.

Previous research suggests that enhancing the volume of a food preload without altering energy content can result in reduced appetite, although the limited evidence means that the conditions under which this effect will occur are not yet clear. In the present study, we used a Universal Eating Monitor (UEM) to record test meal intake constantly, in parallel with appetite ratings, following soup-based preloads that varied both in volume (150 vs. 450 ml) and energy density (1.4 vs. 4.2 kJ/ml). Healthy young men (n=20) received four different preload conditions (repeated measures) followed by unlimited hot pasta test meals (interval 30 min). They completed appetite ratings during and after each laboratory session, and food diaries for the afternoon and evening following each session. Subjective appetite after the preloads was reduced by the high-volume preloads relative to low-volume preloads, with no difference between the two at each volume level. This indicates an effect of volume, but no effect of energy. Test meal intake in the high-volume, high-energy-density condition was reduced relative to the other conditions, which did not differ from one another. This indicates an effect of total energy, but no effect of volume. The dissociation between these different measures of appetite might be explained in terms of largely cognitive influences on subjective appetite between preload and test meal, contrasted with stronger physiological influences on actual intake during the test meal. With regard to previous studies, it is argued that food volume is more influential under circumstances where gastric volume is closer to its normal limits.

Adult↗
PubMed2002

The content of management of violence policy documents in United Kingdom acute inpatient mental health services.

AIM OF THE STUDY: The aim of the study was to examine the content of Trust policies concerning the prevention and management of violence in acute in-patient settings in order to establish their usefulness as guidance for staff in this difficult, complex, and controversial aspect of inpatient psychiatric care. BACKGROUND: Violence is a commonly encountered problem in inpatient psychiatric settings. There are legal requirements for workplaces in general and mental health care facilities in particular to develop safe systems of work based upon the findings of assessments of this risk. Policies have a key role to play in making explicit the responsibilities of both employer and employees, and specifying standards of acceptable practice. DESIGN: A cross-sectional survey methodology was used, which entailed examination of the content of management of violence policies that had been forwarded to the authors from 40 Trusts providing acute inpatient psychiatric care throughout England, Scotland, Wales, and Northern Ireland. FINDINGS: Policies were found to vary widely in their content, and serious shortcomings were noted in the extent to which policies included information regarding their status and review, advice on the prevention of violence, the management of violent incidents, and postincident action. CONCLUSIONS: Further research is needed to tease out the extent to policies which are lacking in content, reflect shortcomings in the organizational approach to the prevention and management of violence by Trusts, and the extent to which such shortcomings result in harm being suffered by staff and/or patients. An alternative format for the presentation of management of violence policies is discussed, and items that should be included in inpatient units' management of violence policies are suggested.

Cross-Sectional Studies↗
PubMed2002

A review of the literature on HIV infection and schizophrenia: implications for research, policy and clinical practice.

AIDS represents one of the major public health problems of the 21st century. Men having sex with men, injecting drug use and having multiple sexual partners are well-established risk behaviours for transmitting the HIV virus. People with schizophrenia are more likely to engage in these behaviours than the general population and as a result there is an increased prevalence of HIV infection in this group. However, many contemporary mental health policy reports fail to discuss the risk of HIV/AIDS in people with schizophrenia, and there are few specific references to sexual health promotion in these documents. People with schizophrenia should be considered an at-risk population for HIV infection and other sexually transmitted diseases. Psychiatric research, policy and clinical practice need to develop rapidly to address this important aspect of a major public health problem.

Female↗
PubMed2002

Recommended standards for reports dealing with arteriovenous hemodialysis accesses.

The incidence rate of treated end-stage renal disease in the united states is 180 per million and continues to rise at a rate of 7.8% per year. Arteriovenous hemodialysis access (AV access) creation and maintenance are two of the most difficult issues associated with the management of patients on hemodialysis. The 1-year complication rate of a primary prosthetic AV access for hemodialysis ranges from 33% to 99%. Various investigators report on patency and complications of AV access. However, it is rather difficult to compare outcomes because of the wide variety of access materials, configurations, locations, risk factors, and quality of inflow and outflow vessels. Although there have been reporting standards for dialysis access endovascular interventions and for central venous access placement, standards regarding surgical access placement and its revision are lacking. The "Dialysis Outcome Quality Initiative," published by the National Kidney Foundation, provides recommendations for optimal clinical practices aimed at improving dialysis outcome and patient survival. This reporting standards document is not meant to be a "practice guidelines" or "best practices" document. Rather, the purpose of this document is to provide standardized definitions related to AV access procedures and to recommend reporting standards for patency and complications, to be used by surgeons, nephrologists, and interventional radiologists, that will permit meaningful comparisons among AV access procedures. The terms, definitions, and categories featured in this article have been approved by the Committee on Reporting Standards of the Society for Vascular Surgery and the American Association for Vascular Surgery and should be observed in preparing manuscripts on AV accesses for submission to the Journal Of Vascular Surgery.

Arteriovenous Shunt, Surgical↗
PubMed2002

Calcium signaling at single mossy fiber presynaptic terminals in the rat hippocampus.

We investigated internal Ca(2+) release at mossy fiber synapses on CA3 pyramidal neurons (mossy fiber terminals, MFTs) in the hippocampus. Presynaptic Ca(2+) influx was induced by giving a brief train of 20 stimuli at 100 Hz to the mossy fiber pathway. Using Ca(2+) imaging techniques, we recorded the Ca(2+) response as DeltaF/F, which increased rapidly with stimulation, but was often accompanied by a delayed peak that occurred after the train. The rise in presynaptic [Ca(2+)] could be completely blocked by application of 400 microM Cd(2+). Furthermore, the evoked Ca(2+) signals were reduced by group II mGluR agonists. Under the same experimental conditions, we investigated the effects of several agents on MFTs that disrupt regulation of intracellular Ca(2+) stores resulting in depletion of internal Ca(2+). We found that ryanodine, cyclopiazonic acid, thapsigargin, and ruthenium red all decreased both the early and the delayed increase in the Ca(2+) signals. We applied D,L-2-amino-5-phosphonovaleric acid (D,L-APV; 50 microM) and 6,7-Dinitroquinoxaline-2,3-dione (DNQX; 20 microM) to exclude the action of N-methyl-D-aspartate (NMDA) and non-NMDA receptors. Experiments with alternative lower affinity indicators for Ca(2+) (fura-2FF and calcium green-2) and the transient K(+) channel blocker, 4-aminopyridine were performed to control for the possible saturation of fura-2. Taken together, these results strongly support the hypothesis that the recorded terminals were from the mossy fibers of the dentate gyrus and suggest that a portion of the presynaptic Ca(2+) signal in response to brief trains of stimuli is due to release of Ca(2+) from internal stores.

2-Amino-5-phosphonovalerate↗
PubMedDate not supplied

Medication management for people with a diagnosis of schizophrenia.

Failure to keep up their antipsychotic medication is a major cause of relapse in people with psychosis. Compliance therapy, a pragmatic intervention based on motivational interviewing and cognitive behavioural therapy, is effective in enhancing concordance and reducing the risk of relapse. There is emerging evidence that after training in medication management, mental health nurses are able to deliver compliance therapy to people with a diagnosis of schizophrenia.

Antipsychotic Agents↗