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Biomedical subjects

R Lewis

Publications and source records attributed to R Lewis.

At least 37 records · Page 2Linked to original sources
PubMed2001

Venous thromboembolism after acute stroke.

BACKGROUND: Treatment for venous thromboembolism (VTE) is highly effective in preventing morbidity and mortality, yet pulmonary embolism (PE) accounts for up to 25% of early deaths after stroke. This is because the current diagnostic paradigm is reactive rather than proactive: the clinician responds to VTE when it becomes symptomatic, in the expectation that initiation of treatment will prevent progression to more serious manifestations. This approach is flawed, because sudden death from PE is frequently unheralded and nonfatal symptomatic pulmonary emboli are often unrecognized or misdiagnosed. SUMMARY OF COMMENT: Morbidity and mortality from PE could be reduced either by more effective thromboprophylaxis or earlier diagnosis and treatment of established VTE. The fact that early use of short-term, low-dose, unfractionated heparin (UFH) is not associated with sustained, clinically meaningful benefit suggests that a fundamental change in the diagnostic approach to VTE is needed, one which requires a greater appreciation that clinically apparent events are merely the tip of the thromboembolism iceberg. CONCLUSIONS: Research into a strategy of screening for subclinical VTE in these patients is needed, with a view to identifying a subgroup at risk of progression to symptomatic and life-threatening events, in whom outcome might be improved by anticoagulation.

Anticoagulants↗
PubMed2001

The national health service plan: further reform of British health care?

Less than three years after initiating a series of health service reforms, the Blair government has launched another plan for the U.K. National Health Service. This article considers the origins and contents of the plan. A major investment program is designed to bring health care spending up to European averages over the next five years. In return, the government seeks to challenge the existing settlement between organized medicine and the state through tighter regulatory control, altered contractual frameworks, and a new public-private concordat. The plan does not represent a radical change in government policy but rather reaffirms existing approaches to increasing access to health services, integrating health and social care, and empowering users. Notwithstanding arrangements to increase the autonomy of health service organizations, the plan increases central control through a range of new bodies and regulatory frameworks. It represents an incremental adjustment of the existing tax-funded system. Should this reinvigoration of the state monopoly fail, alternative sources of funding will no doubt have to be reconsidered.

Comprehensive Health Care↗
PubMed2001

A rapid and systematic review of the clinical effectiveness and cost-effectiveness of debriding agents in treating surgical wounds healing by secondary intention.

BACKGROUND: Most surgically sutured wounds heal without any complication. However, in some cases wound healing can be delayed due to the presence of infection or wound breakdown. This can result in the wounds becoming cavity wounds and thus necessitate healing by secondary intention. Other surgical wounds that are not sutured but left to heal by secondary intention include abscess cavities such as perianal abscesses or breast abscesses. Surgical wounds healing by secondary intention are thought to heal more slowly than wounds healing by primary intention, especially if infection is present or healing is compromised by factors such as decreased blood supply, poor nutritional status or a general suppression of the immune response. Such wounds may contain dead tissue and have a moderate or high level of exudate. Debridement involves the removal of devitalised, necrotic tissue or fibrin from a wound. There are many different methods that can be used to debride a wound, which are broadly classified as surgical/sharp, biosurgical, mechanical, chemical, enzymatic and autolytic. Although it is generally agreed that the management of surgical wounds which contain devitalised tissue and are healing by secondary intention requires debridement, it is not always clear as to what is the best method or agent to use. There is currently a large selection of products with debriding properties available on the market, which vary considerably in cost. It is important that the choice of both debriding method and product is based on the best scientific evidence available, taking into account both cost and effectiveness data. OBJECTIVES: The review had two main objectives: (1) To determine the clinical effectiveness and cost-effectiveness of debriding agents in treating surgical wounds healing by secondary intention. (2) To evaluate the clinical effectiveness and cost-effectiveness of treating patients with surgical wounds healing by secondary intention at specialised wound care clinics as compared to conventional care. The review incorporated all debriding methods and any agent that is considered to have a debriding property. METHODS The following databases were searched using strategies designed specifically for each database: MEDLINE, EMBASE, CINAHL, HMIC (Health Management Information Consortium), CCTR via the Cochrane Library, the National Research Register (NRR), the NHS Economic Evaluation Database (NHS EED), and the Health Economic Evaluations Database (HEED). Additional references were identified through reviewing manufacturer and sponsor submissions made to NICE, the bibliographies of retrieved articles, and conferences proceedings on the Internet. Only randomised controlled trials (RCTs) or non-randomised controlled trials with concurrent controls and full economic evaluations were considered for inclusion. Only studies that evaluated some sort of debriding method or a specialised wound care clinic (a nurse with specialist training in wound care; care being provided by a multidisciplinary team; a fast-track referral system to other professions (e.g. dermatologist); or access to the latest health technology) were included in the review. Studies had to include participants with surgical wounds healing by secondary intention (e.g. cavity wounds, the consequences of wound dehiscence and abscesses) and report an objective measure of wound healing. Data were extracted by one reviewer and checked by a second. Quality assessment was conducted independently by two reviewers. Disagreements were resolved by consensus and, when necessary, by recourse to a third reviewer. The primary outcomes of interest were wound healing and cost. Results of data extraction and quality assessment were presented in structured tables and also as a narrative summary. In addition, where feasible, the results of individual studies were presented as forest plots. Studies were grouped according to the type of wound, debriding method and outcome measure used. RESULTS - CLINICAL EFFECTIVENESS: Seventeen trials met the inclusion criteria, all of which used the autolytic method of debridement. No studies were found that investigated sharp/surgical, biosurgical, mechanical, chemical or enzymatic debridement in the treatment of surgical wounds healing by secondary intention. No studies were found which investigated specialised wound care clinics that included the provision of care within a clinical setting (based in either primary or secondary care). The type of surgical wounds investigated by studies included in the review were those that had broken down postoperatively, perineal wounds resulting from proctolectomy or rectal excision, and those left open after pilonidal sinus excision or abscess incision, or wounds following a laparotomy. Four additional studies investigated treatment of postoperative wounds from toenail avulsions. (ABSTRACT TRUNCATED)

Clinical Trials as Topic↗
PubMed2000

A voxel-by-voxel analysis of [18F]setoperone PET data shows no substantial serotonin 5-HT(2A) receptor changes in schizophrenia.

Several postmortem studies have reported regionally localized decreases in serotonin(2A) receptors (5-HT(2A)R) in schizophrenia. This was not confirmed by two recent [18F]setoperone positron emission tomography (PET) studies. In these two studies relatively large regions of interest (ROIs) were used; hence, 5-HT(2A)R changes may have been missed in some brain areas. Therefore, data from one study were analyzed on a voxel-by-voxel basis using Statistical Parametric Mapping (SPM). We also used this method to examine the relationship between 5-HT(2A)R binding potential (BP) and five PANSS-derived factors: negative, positive, activation, dysphoric and autistic preoccupation. Thirteen schizophrenic patients (10 antipsychotic-naïve, 3 antipsychotic-free; 11 M, 2 F; age 31+/-7 years) and 35 age-matched control subjects (15 M, 20 F; age 30+/-7 years) were scanned. The 5-HT(2A)R BP was determined for each voxel using the pseudoequilibrium ratio method on PET data obtained between 65 and 90 min after [18F]setoperone bolus injection. The resulting parametric 5-HT(2A)R BP images were spatially normalized using a ligand specific template. Analyses of covariance were done using SPM99 with age as covariate. In tests for the effect of schizophrenia and for partial correlations between 5-HT(2A)R BP and the five factors, corrected P values <0.05 at cluster or voxel level were considered significant. No significant differences were detected between patients and control subjects, and no significant correlations were observed between 5-HT(2A)R BP and any of the five factors. Thus, in agreement with the previous ROI studies, voxel-by-voxel analysis confirmed the lack of substantial 5-HT(2A)R BP differences between schizophrenic patients and control subjects.

Adult↗
PubMed2000

Doctors' pay. What seems to be the trouble?

The long-standing method of paying GPs through a complex system of fees and allowances is under review. The proposed expansion of personal medical services pilots and an increase in the number of salaried GPs could destabilise the current system and lead to perverse outcomes. The introduction of a weighted capitation system allocating resources to health authorities and primary care trusts according to need might ensure equitable distribution of funds.

Family Practice↗
PubMed2000

Sertindole for schizophrenia.

BACKGROUND: Sertindole is an atypical antipsychotic, which is thought to give a lower incidence of extrapyramidal side effects at clinically effective doses than typical antipsychotic drugs. In December 1998, Lundbeck Ltd., the manufacturers of sertindole, voluntarily suspended the availability of the drug due to concerns about cardiac arrhythmia and sudden cardiac death associated with its use. Sertindole has therefore been withdrawn from the market pending discussion with the European Regulatory Authority over cardiac safety. OBJECTIVES: To determine the effects of sertindole compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and related psychoses. SEARCH STRATEGY: Electronic searches of Biological Abstracts (1980-1999), The Cochrane Library (Issue 1, 1999), The Cochrane Schizophrenia Group's Register (January 1999), EMBASE (1980-1999), LILACS (1982-1996), MEDLINE (1966-1999), PSYNDEX (1977-1995) and PsycLIT (1974-1999) were undertaken. In addition, pharmaceutical databases on the Dialog Corporation Datastar and Dialog services were searched. References of all identified studies were searched for further trials. The manufacturer of sertindole and authors of trials were contacted. SELECTION CRITERIA: All randomised controlled trials that compared sertindole to placebo or other antipsychotic drug treatments were included by independent assessment. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted. For homogeneous dichotomous data the risk ratio (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) or numbers needed to harm (NNH) were calculated on an intention-to-treat basis. For continuous data, weighted mean differences (WMD) were calculated. All data were inspected for heterogeneity. MAIN RESULTS: Two large important studies were excluded, because they did not report any usable data. The two that were included suggested that sertindole was more antipsychotic than placebo, as acceptable as placebo and better tolerated than haloperidol (NNT=9, RR 0.63 CI 0.41 to 0.96). Sertindole was associated with fewer movement disorders than haloperidol but was shown to cause more weight gain (NNH=9 RR 6.33, CI 1.92 to 20.92), rhinitis (NNH=8, RR 1.74, CI 1,28 to 2.36) and possibly male sexual dysfunction. Cardiac problems (QTc intervals of at least 500msec) were evident even in the randomised trials (NNH=13 RR 23, CI 1.37 to 386.60). REVIEWER'S CONCLUSIONS: Because of the cardiac problems, even evident within poorly reported studies, at present sertindole should, if possible, be avoided. If sertindole is to be reintroduced, gold-standard evidence of its clinical benefits will need to far outweigh its real risks.

Antipsychotic Agents↗
PubMed2000

Molindone for schizophrenia and severe mental illness.

BACKGROUND: Typical antipsychotic drugs are widely used as the first line treatment for people with schizophrenia. However, the atypical class of antipsychotic drugs is making important inroads into this approach. 'Atypical' is a term widely used to describe some antipsychotics which have a low propensity to produce movement disorders, sedation and raised serum prolactin. There is some suggestion that the different adverse effect profiles of the atypical antipsychotic group make them more acceptable to people with schizophrenia. Molindone has a similar profile to quetiapine (a novel atypical antipsychotic), with very low binding to all receptors. Some authors have suggested that molindone is safer than other 'typical' antipsychotics in that extrapyramidal adverse effects are not usually seen at clinically effective antipsychotic doses and that it should therefore be classed as an atypical antipsychotic. OBJECTIVES: To determine the effects of molindone compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and related psychoses. SEARCH STRATEGY: Electronic searches of Biological Abstracts (1980-1999), The Cochrane Library CENTRAL (Issue 1, 1999), The Cochrane Schizophrenia Group's Register (January 1999), CINAHL (1982-1999), EMBASE (1980-1999), MEDLINE (1966-1999), LILACS (1982-1999), PSYNDEX (1977-1999), and PsycLIT (1974-1999) were undertaken. In addition, pharmaceutical databases on the Dialog Corporation Datastar and Dialog services were searched. References of all identified studies were searched for further trials. The manufacturer of molindone and authors of trials were contacted. SELECTION CRITERIA: All randomised controlled trials that compared molindone to other treatments for schizophrenia and schizophrenia-like psychoses were included by independent assessment. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted. Data were excluded if loss to follow up was greater than 50%. For homogeneous dichotomous data the risk ratio (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, weighted mean differences (WMD) were calculated. All data were inspected for heterogeneity. MAIN RESULTS: Thirteen studies were included in the review. Data for this compound range from very short (10 day) studies of the intramuscular preparation to trials lasting over three months. For measures of global state available data do not justify any conclusions on the comparative efficacy of molindone and placebo. When compared to other typical antipsychotics no difference in effectiveness was evidenced (doctors' RR 1.13, CI 0.69 to 1.86; nurses' RR 1.23, CI 0.82 to 1.86). It is no more or less likely than typical drugs to cause movement disorders, but causes significantly more weight loss (RR 2.78, CI 1.10 to 6.99). REVIEWER'S CONCLUSIONS: The strength of the evidence relating to this compound is limited, owing to small sample size, poor study design, limited outcomes and incomplete reporting. Molindone may be an effective antipsychotic; however, its adverse effect profile does not differ significantly from that of typical antipsychotics, apart from the event of weight loss. At present there is no evidence to suggest that it may have an atypical profile.

Antipsychotic Agents↗
PubMed2000

Telemedicine versus face to face patient care: effects on professional practice and health care outcomes.

BACKGROUND: Telemedicine is the use of telecommunications technology for medical diagnosis and patient care. From its beginnings telemedicine has been used in a variety of health care fields, although widespread interest among healthcare providers has only now become apparent with the development of more sophisticated technology. OBJECTIVES: To assess the effects of telemedicine as an alternative to face-to-face patient care. SEARCH STRATEGY: We searched the Effective Practice and Organisation of Care Group's specialised register, The Cochrane Library, MEDLINE (1966-August 1999), EMBASE (to 1996), Cinahl (to August 1999), Inspec (to August 1996), Healthstar (1983-1996), OCLC, Sigle (to 1999), Assia, SCI (1981-1997), SSCI (1981-1997), DHSS-Data. We hand searched the Journal of Telemedicine and Telecare (1995-1999), Telemedicine Journal (1995-1999) and reference lists of articles. We also hand searched conference proceedings and contacted experts in countries identified as having an interest in telemedicine. SELECTION CRITERIA: Randomised trials, controlled before and after studies and interrupted time series comparing telemedicine with face-to-face patient care. The participants were qualified health professionals and patients receiving care through telemedicine. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. MAIN RESULTS: Seven trials involving more than 800 people were included. One trial was concerned with telemedicine in the emergency department, one with video-consultations between primary health care and the hospital outpatients department, and the remainder were concerned with the provision of home care or patient self-monitoring of chronic disease. The studies appeared to be well conducted, although patient numbers were small in all but one. Although none of the studies showed any detrimental effects from the interventions, neither did they show unequivocal benefits and the findings did not constitute evidence of the safety of telemedicine. None of the studies included formal economic analysis. All the technological aspects of the interventions appear to have been reliable, and to have been well accepted by patients. REVIEWER'S CONCLUSIONS: Establishing systems for patient care using telecommunications technologies is feasible, but there is little evidence of clinical benefits. The studies provided variable and inconclusive results for other outcomes such as psychological measures, and no analysable data about the cost effectiveness of telemedicine systems. The review demonstrates the need for further research and the fact that it is feasible to carry out randomised trials of telemedicine applications. Policy makers should be cautious about recommending increased use and investment in unevaluated technologies.

Communication↗
PubMed2000

CNS acetylcholine receptor activity in European medicinal plants traditionally used to improve failing memory.

Certain Lamiaceous and Asteraceous plants have long histories of use as restoratives of lost or declining cognitive functions in western European systems of traditional medicine. Investigations were carried out to evaluate human CNS cholinergic receptor binding activity in extracts of those European medicinal plants reputed to enhance or restore mental functions including memory. Ethanolic extracts were prepared from accessions of these plants and a number of other species related by genus. Amongst the plant extracts screened for contents able to displace [3H]-(N)-nicotine and [3H]-(N)-scopolamine from nicotinic receptors and muscarinic receptors, respectively in homogenates of human cerebral cortical cell membranes, the most potent extracts, prepared from one accession of Melissa officinalis, three Salvia species and Artemisia absinthium had IC50 concentrations of < 1 mg/ml. The displacement curves of some extracts were comparable with that of carbamylcholine chloride, a potent acetylcholine analogue. Choline, a weak nicotinic ligand (IC50 = 3 x 10(-4) M) was found in extracts of all plants studied at concentrations of 10(-6)-10(-5) M. These concentrations could not account for not more than 5% of the displacement activity observed. Some extracts displayed differential displacement at nicotinic and muscarinic acetylcholine receptors, with M. officinalis 0033 having the highest [3H]-(N)-nicotine displacement value and Salvia elegans with the highest [3H]-(N)-scopolamine displacement value. There was also considerable variation in cholinoreceptor interactions between different accessions of a single plant species. Although most plant extracts screened showed some nicotinic and muscarinic activity, only some showed dose-dependent receptor activity typical of materials with genuine cholinergic activity.

Asteraceae↗
PubMed2000

Roles for ephrins in positionally selective synaptogenesis between motor neurons and muscle fibers.

Motor axons form topographic maps on muscles: rostral motor pools innervate rostral muscles, and rostral portions of motor pools innervate rostral fibers within their targets. Here, we implicate A subfamily ephrins in this topographic mapping. First, developing muscles express all five of the ephrin-A genes. Second, rostrally and caudally derived motor axons differ in sensitivity to outgrowth inhibition by ephrin-A5. Third, the topographic map of motor axons on the gluteus muscle is degraded in transgenic mice that overexpress ephrin-A5 in muscles. Fourth, topographic mapping is impaired in muscles of mutant mice lacking ephrin-A2 plus ephrin-A5. Thus, ephrins mediate or modulate positionally selective synapse formation. In addition, the rostrocaudal position of at least one motor pool is altered in ephrin-A5 mutant mice, indicating that ephrins affect nerve-muscle matching by intraspinal as well as intramuscular mechanisms.

Animals↗
PubMed2000

Review of intraurethral suppositories and iontophoresis therapy for erectile dysfunction.

This brief review examines the history of the intraurethral (IU) pharmacotherapy for the treatment of erectile dysfunction (ED). Emphasis is placed on the design, study endpoints and results of a limited number of clinical trials undertaken with PGE(1)-MUSE to demonstrate the efficacy of this unique delivery system. Next, the theory of the iontophoretic technique of drug delivery is discussed. Clinical data collected while applying these methods are presented, but are thus far limited to treatment of patients with Peyronie's disease. Iontophoresis as a drug delivery alternative may gain popularity with ED patients who fail other types of therapy or in patients with other penile disorders. International Journal of Impotence Research (2000) 12, Suppl 4, S86-S90.

Alprostadil↗
PubMed2000

Accuracy of the OMRON M4 automatic blood pressure measuring device.

Despite widespread use of the automatic blood pressure (BP) measuring device OMRON M4, there is little formal validation on its accuracy. A study was conducted to assess the accuracy of the OMRON M4 compared with the true indirect BP measured by mercury sphygmomanometer (MS). A rapid method for the evaluation of automatic blood pressure measurement devices (READ) was applied for this study. The READ is based on numerous BP measurements at rest and during a standardised postural challenge in a small number of subjects who exhibit a wide range of BPs. Blood pressure measurements were done in supine position for 10 min followed by head-up tilt for 30 min and again supine for 10 min. The automatic device (AU) and the MS were connected to one arm-cuff by means of a T connector. A stethoscope with dual sets of ear-pieces was used for duplicate MS measurements (MS1 and MS2). The MS1, MS2 and AU measurements were taken simultaneously in a blinded manner. Three units of the automatic instrument were evaluated. An average of 111 measurements per unit were performed, every BP category being present in >/=15 MS measurements. The differences between MS1 and MS2 measurements (DeltaBP: MS1-MS2) were utilized to assess the consistency of true indirect BP and the differences between AU and MS measurements (DeltaBP:AU-MS2) were utilized to assess the accuracy of the AU. The following characteristics of the OMRON M4 were assessed: (1) grade of accuracy, (2) aberration pattern, (3) consistency of the aberration-pattern, and (4) correlation between levels of BP and DeltaBP: AU-MS. For MS paired readings, 92-100% of systolic and 99-100% of diastolic readings fell within 5 mm Hg difference range, that is consistent with a British Hypertension Society grade A of both. For AU compared to MS2, 29-64% of systolic and 73-94% of diastolic readings fell within 5 mm Hg and 49-86% of systolic and 86-99% of diastolic readings fell within 10 mm Hg and the devices qualified C, D and C, respectively. All devices exhibited irregular and inconsistent aberration patterns, making the design of correction formulas impractical. In conclusion, the OMRON M4 device did not meet the requirements of the British Hypertension Society and, therefore, cannot be recommended for clinical use.

Adult↗
PubMed2000

Consumer demand in the purchase and prescription of sugar-free medicines.

OBJECTIVES: To determine the current level of consumer demand in the purchase and prescription of sugar-free paediatric medicines. DESIGN: Data were collected by administered questionnaire. SETTING: The study was conducted in a Hospital Paediatric Dentistry Unit and a Community Dental Clinic, both within the Bro Taf area of south-east Wales. SAMPLE AND METHODS: The parents of 240 children attending for routine dental care responded to one of two short questionnaires, depending on whether their child had received a liquid oral medicine in the preceding month. RESULTS: Although aware of the benefits of sugar-free medicines, parents did not appear to be attempting to exercise the power of consumer demand to its full potential. They were more likely to ask a pharmacist (or pharmacist's assistant) than their general medical practitioner for a sugar-free medicine. CONCLUSIONS: We must continue to promote sugar-free medicines. While increasing the importance that health professionals attach to such products, future campaigns should also aim to increase consumer demand.

Administration, Oral↗
PubMed2000

Diabetic emergencies: Part 2. Hyperglycaemia.

Part 2 of this series explores the pathophysiology and clinical management of diabetic emergencies involving hyperglycaemia, including both diabetic ketoacidosis and the rarer hypernatremic, non-ketotic coma. Part 1 (Hypoglycaemia) was published in Accident and Emergency Nursing 7(4): 190-196.

Blood Glucose↗
PubMed2000

Effectiveness of incidence thresholds for detection and control of meningococcal meningitis epidemics in northern Togo.

BACKGROUND: Early outbreak detection is necessary for control of meningococcal meningitis epidemics. A weekly incidence of 15 cases per 100 000 inhabitants averaged over 2 consecutive weeks is recommended by the World Health Organization (WHO) for detection of meningitis epidemics in Africa. This and other thresholds are tested for ability to predict outbreaks and timeliness for control measures. METHODS: Meningitis cases recorded for 1990-1997 in health centres of northern Togo were reviewed. Weekly and annual incidences were determined for each district. Ability of different weekly incidence thresholds to detect outbreaks was assessed according to sensitivity, specificity, and positive and negative predictive values. The number of cases potentially prevented by reactive vaccination in 1997 was calculated for each threshold. RESULTS: Outbreaks occurred in 1995-1996 and in 1996-1997. The WHO-recommended threshold had good specificity but low sensitivity. Thresholds of 10 and 7 cases per 100,000 inhabitants in one week had sensitivity and specificity of 100% and increased the time available for intervention by more than one or two weeks, respectively. A maximum of 65% of cases could have been prevented during the 1997 epidemic, with up to 8% fewer cases prevented for each week of delay in achieving vaccine coverage. CONCLUSIONS: In northern Togo, thresholds of 7 or 10 cases per 100,000 inhabitants per week were excellent predictors of meningitis epidemics and allowed more time for a reactive vaccination strategy than current recommendations.

Disease Outbreaks↗