Site-selective measurement of coupled spin pairs in an organic semiconductor.

From organic electronics to biological systems, understanding the role of intermolecular interactions between spin pairs is a key challenge. Here we show how such pairs can be selectively addressed with combined spin and optical sensitivity. We demonstrate this for bound pairs of spin-triplet excitations formed by singlet fission, with direct applicability across a wide range of synthetic and biological systems. We show that the site sensitivity of exchange coupling allows distinct triplet pairs to be resonantly addressed at different magnetic fields, tuning them between optically bright singlet ([Formula: see text]) and dark triplet quintet ([Formula: see text]) configurations: This induces narrow holes in a broad optical emission spectrum, uncovering exchange-specific luminescence. Using fields up to 60 T, we identify three distinct triplet-pair sites, with exchange couplings varying over an order of magnitude (0.3-5 meV), each with its own luminescence spectrum, coexisting in a single material. Our results reveal how site selectivity can be achieved for organic spin pairs in a broad range of systems.

Spin Fine Structure Reveals Biexciton Geometry in an Organic Semiconductor.

In organic semiconductors, biexcitons are key intermediates in carrier multiplication and exciton annihilation. Their local geometry governs their electronic properties and yet has been challenging to determine. Here, we access the structure of the recently discovered S=2 quintet biexciton state in an organic semiconductor using broadband optically detected magnetic resonance. We correlate the experimentally extracted spin structure with the molecular crystal geometry to identify the specific molecular pairings on which biexciton states reside.

Optically addressable molecular spins for quantum information processing.

Spin-bearing molecules are promising building blocks for quantum technologies as they can be chemically tuned, assembled into scalable arrays, and readily incorporated into diverse device architectures. In molecular systems, optically addressing ground-state spins would enable a wide range of applications in quantum information science, as has been demonstrated for solid-state defects. However, this important functionality has remained elusive for molecules. Here, we demonstrate such optical addressability in a series of synthesized organometallic, chromium(IV) molecules. These compounds display a ground-state spin that can be initialized and read out using light and coherently manipulated with microwaves. In addition, through atomistic modification of the molecular structure, we vary the spin and optical properties of these compounds, indicating promise for designer quantum systems synthesized from the bottom-up.

Structural neuroimaging in psychosis: a systematic review and economic evaluation.

OBJECTIVES: To establish the clinical effectiveness and cost-effectiveness of structural neuroimaging [structural magnetic resonance imaging (MRI) or computed tomography (CT) scanning] for all patients with psychosis, particularly a first episode of psychosis, relative to the current UK practice of selective screening only where it is clinically indicated. DATA SOURCES: Major electronic databases were searched from inception to November 2006. REVIEW METHODS: A systematic review of studies reporting the additional diagnostic benefit of structural MRI, CT or combinations of these in patients with psychosis was conducted. The economic assessment consisted of a systematic review of economic evaluations and the development of a threshold analysis to predict the gain in quality-adjusted life-years (QALYs) required to make neuroimaging cost-effective at commonly accepted threshold levels (20,000 pounds and 30,000 pounds per QALY). Sensitivity analyses of several parameters including prevalence of psychosis were performed. RESULTS: The systematic review included 24 studies of a diagnostic before-after type of design evaluating the clinical benefit of CT, structural MRI or combinations in treatment-naive, first-episode or unspecified psychotic patients, including one in schizophrenia patients resistant to treatment. Also included was a review of published case reports of misidentification syndromes. Almost all evidence was in patients aged less than 65 years. In most studies, structural neuroimaging identified very little that would influence patient management that was not suspected based on a medical history and/or physical examination and there were more incidental findings. In the four MRI studies, approximately 5% of patients had findings that would influence clinical management, whereas in the CT studies, approximately 0.5% of patients had these findings. The review of misidentification syndromes found that 25% of CT scans affected clinical management, but this may have been a selected and therefore unrepresentative sample. A threshold analysis with a 1-year time horizon was undertaken. This combined the incremental cost of routine scanning with a threshold cost per QALY value of 20,000 pounds and 30,000 pounds to predict the QoL gain required to meet these threshold values. Routine scanning versus selective scanning appears to produce different results for MRI and CT. With MRI scanning the incremental cost is positive, ranging from 37 pounds to 150 pounds; however, when scanning routinely using CT, the result is cost saving, ranging from 7 pounds to 108 pounds with the assumption of a 1% prevalence rate of tumours/cysts or other organic causes amenable to treatment. This means that for the intervention to be viewed as cost-effective, the QALY gain necessary for MRI scanning is 0.002-0.007 and with CT scanning the QALY loss that can be tolerated is between 0.0003 and 0.0054 using a 20,000 pounds threshold value. These estimates were subjected to sensitivity analysis. With a 3-month time delay, MRI remains cost-incurring with a small gain in QoL required for the intervention to be cost-effective; routine scanning with CT remains cost-saving. When the sensitivity of CT is varied to 50%, routine scanning is both cost-incurring or cost-saving depending on the scenario. Finally, the results have been shown to be sensitive to the assumed prevalence rate of brain tumours in a psychotic population. CONCLUSIONS: The evidence to date suggests that if screening with structural neuroimaging was implemented in all patients presenting with psychotic symptoms, little would be found to affect clinical management in addition to that suspected by a full clinical history and neurological examination. From an economic perspective, the outcome is not clear. The strategy of neuroimaging for all is either cost-incurring or cost-saving (dependent upon whether MRI or CT is used) if the prevalence of organic causes is around 1%. However, these values are nested within a number of assumptions, and so have to be interpreted with caution. The main research priorities are to monitor the current use of structural neuroimaging in psychosis in the NHS to identify clinical triggers to its current use and subsequent outcomes; to undertake well-conducted diagnostic before-and-after studies on representative populations to determine the clinical utility of structural neuroimaging in this patient group, and to determine whether the most appropriate structural imaging modality in psychosis should be CT or MRI.

Room temperature magneto-optic effect in silicon light-emitting diodes.

In weakly spin-orbit coupled materials, the spin-selective nature of recombination can give rise to large magnetic-field effects, e.g. on the electro-luminescence of molecular semiconductors. Although silicon has weak spin-orbit coupling, observing spin-dependent recombination through magneto-electroluminescence is challenging: silicon's indirect band-gap causes an inefficient emission and it is difficult to separate spin-dependent phenomena from classical magneto-resistance effects. Here we overcome these challenges and measure magneto-electroluminescence in silicon light-emitting diodes fabricated via gas immersion laser doping. These devices allow us to achieve efficient emission while retaining a well-defined geometry, thus suppressing classical magnetoresistance effects to a few percent. We find that electroluminescence can be enhanced by up to 300% near room temperature in a seven Tesla magnetic field, showing that the control of the spin degree of freedom can have a strong impact on the efficiency of silicon LEDs.

Systematic review of the effectiveness of community-based self-management interventions among primary care COPD patients.

COPD self-management reduces hospital admissions and improves health-related quality of life (HRQoL). However, whilst most patients are managed in primary care, the majority of self-management trials have recruited participants with more severe disease from secondary care. We report the findings of a systematic review of the effectiveness of community-based self-management interventions in primary care patients with COPD. We systematically searched eleven electronic databases and identified 12 eligible randomised controlled trials with seven included in meta-analyses for HRQoL, anxiety and depression. We report no difference in HRQoL at final follow-up (St George's Respiratory Questionnaire total score -0.29; 95%CI -2.09, 1.51; I2 0%), nor any difference in anxiety or depression. In conclusion, supported self-management interventions delivered in the community to patients from primary care do not appear to be effective. Further research is recommended to identify effective self-management interventions suitable for primary care populations, particularly those with milder disease.

Oral naltrexone as a treatment for relapse prevention in formerly opioid-dependent drug users: a systematic review and economic evaluation.

OBJECTIVES: To investigate the clinical effectiveness and cost-effectiveness of naltrexone for relapse prevention in detoxified formerly opioid-dependent individuals compared with any strategy that does not use naltrexone, including treatment with placebo, other pharmacological treatments, psychosocial interventions or no treatment. DATA SOURCES: Major electronic databases were searched from inception to September 2005. REVIEW METHODS: Selected studies were screened and quality assessed. Meta-analyses were carried out as appropriate. A decision-analytic model using Monte Carlo simulation was developed that compared naltrexone as an adjunctive therapy to no naltrexone. It assumed compliance rates that were not enhanced by contingent management rewards (because this is current UK practice). Utility values could not be identified from the literature and so were obtained by research specially commissioned from the Value of Health Panel. RESULTS: The methodological quality of the 26 randomised controlled trials (RCTs) that met the inclusion criteria was poor to moderate. The results suggest that naltrexone as maintenance therapy may be better than placebo in terms of retention in treatment, but this was not statistically significant. A meta-analysis of seven included RCTs gave the relative risk (RR) of loss of retention in treatment in the naltrexone arm as 0.94. The pooled hazard ratio (HR) reported in five of the RCTs for retention in treatment data followed up to 35 weeks was calculated as 0.90 in favour of naltrexone and also did not reach statistical significance. The risk of drug abuse in naltrexone versus placebo, with or without psychological support given in both arms, gave a pooled RR of 0.72, which was a statistically significant difference in favour of naltrexone. The pooled HR from three RCTs for opioid relapse-free rates was significantly different from placebo in favour of naltrexone 0.53; however, this fell off over time and may be of limited clinical significance. The RR of reimprisonment while on naltrexone therapy showed results in favour of naltrexone in the combined two studies of parolees or people on probation, but the number of participants was small. One study of 52 participants found that the difference in improvement score for risky sexual behaviour in the naltrexone group compared with the placebo group was not statistically significant. The adverse events data reported showed no significant difference between the naltrexone and placebo arms. The quality of the nine RCTs of interventions designed to increase retention with naltrexone was poor to moderate; however, all three different modalities of enhanced care showed some evidence of effectiveness. All of the contingency management programmes used incentive vouchers; the mean duration of treatment retention was 7.4 weeks for the contingency management intervention compared with 2.3-5.6 weeks for the naltrexone treatment alone. The mean length of time for which patients stayed on naltrexone was 84-103 days with additional psychosocial therapy compared with 43-64 days for the control group. In trials with added pharmacological agents the RRs of stopping treatment were 1.63 at 6 months and 1.31 at 12 months (in favour of naltrexone plus fluoxetine). It became statistically significant at 6 months, but not at 12 months. A meta-analysis of the RR of stopping treatment at week 12 (the minimum follow-up period) was carried out using six of the nine studies. The pooled RR of stopping treatment was 0.81. The results indicated that overall the intervention groups had 19% fewer patients who stopped treatment compared with the control group, but there was only a small number of studies and their quality was relatively poor. No existing economic evaluations were identified. The point estimate for the cost-effectiveness of naltrexone was pound42,500 per quality-adjusted life-year (QALY). Sensitivity analysis was carried out and the incremental cost-effectiveness ratio varied between pound34,600 and pound42,500 per QALY gained. CONCLUSIONS: Following successful withdrawal from opioids, naltrexone may be administered on a chronic basis to block any future effects of opioids. Naltrexone appears to have some limited benefit in helping formerly opioid-dependent individuals to remain abstinent, although the quality of the evidence is relatively poor and heterogeneous. The limited quality and extent of the studies precluded an analysis of subgroups likely to benefit from naltrexone prescribing. Oral naltrexone is used infrequently in current UK practice, and this review suggests that this is appropriate as there is little evidence to support its wider implementation. There is an important deficit in information about the quality of life of people who use illicit opioids and this would perhaps be a worthwhile area of research in informing policy questions about the cost-effectiveness of different programmes and interventions.

A systematic review and economic model of the clinical and cost-effectiveness of immunosuppressive therapy for renal transplantation in children.

OBJECTIVES: To review the clinical and cost-effectiveness of basiliximab, daclizumab, tacrolimus, mycophenolate mofetil (MMF), mycophenolate sodium (MPS) and sirolimus as possible immunosuppressive therapies for renal transplantation in children. DATA SOURCES: Electronic databases were searched up to November 2004. REVIEW METHODS: Data from selected studies were extracted and quality assessed. An economic model [Birmingham Sensitivity Analysis paediatrics (BSAp)] was produced based on an adaptation of a model previously developed for the assessment of the cost-effectiveness of immunosuppressants in adults following renal transplant. RESULTS: For the addition of basiliximab, one unpublished paediatric randomised control trial (RCT), reported that the addition of basiliximab to tacrolimus-based triple therapy (BTAS) failed to significantly improve 6-month biopsy-proven acute rejection (BPAR), graft function, graft loss and all-cause mortality. No significant difference between groups was seen in 6-month or 1-year or longer graft loss, all-cause mortality and side-effects. In a meta-analysis of adult RCTs, the addition of basiliximab to a ciclosporin, azathioprine and steroid regimen (CAS) significantly reduced short-term BPAR. There was no significant difference in short- or long-term graft loss, all-cause mortality or side-effects. One adult RCT was included for the addition of daclizumab to CAS, which reported reduced 1-year BPAR, although no difference between groups was seen in either 1- or 3-year graft loss, all-cause mortality and side-effects. For tacrolimus versus ciclosporin, one unpublished paediatric RCT found that a regimen of tacrolimus, azathioprine and a steroid (TAS) reduced 6-month BPAR and improved graft function [glomerular filtration rate (GFR)] compared with CAS. This improvement in BPAR with tacrolimus was as shown in the meta-analysis of adult RCTs. There was evidence, particularly in children, that in comparison with ciclosporin, tacrolimus may reduce long-term graft loss, although there is no benefit on total mortality. The total level of withdrawal in children was reduced in children receiving tacrolimus. Adult RCTs showed an increase in post-transplant diabetes mellitus with tacrolimus. For MMF versus azathioprine, a meta-analysis of adult RCTs showed MMF [regimen of ciclosporin, MMF and a steroid (CMS)] to reduce 1-year BPAR compared with azathioprine (CAS). There was evidence, particularly in children, that in comparison with azathioprine, tacrolimus may reduce long-term graft loss, although there is no benefit on total mortality. There was an increase in the level of cytomegalovirus infection with MMF, although the overall level of withdrawal due to adverse events was not different to that of azathioprine-treated adults. No study comparing MPS with azathioprine (CAS) was identified. In an adult RCT comparing MMF with MPS, there was no significant difference between groups in 1-year efficacy or side-effects. One unpublished paediatric RCT assessed the addition of sirolimus to CAS. BPAR, graft loss and all-cause mortality were not reported. In two adult RCTs, compared with azathioprine, sirolimus reduced 1-year BPAR, reduced graft function (as assessed by an increased serum creatinine) and increased the level of hyperlipidaemia. No significant differences were seen in other efficacy and side-effect outcomes. On an adult RCT comparing sirolimus with ciclosporin, there were no significant differences between groups in 1-year efficacy or side-effects with the exception of an increased level of hyperlipidaemia with sirolimus substitution. Both the assessment group and drug companies assessed the cost-effectiveness of the newer renal immunosuppressants currently licensed in children using an adaptation (BSAp) of the Birmingham Sensitivity Analysis (BSA) model. This model is based on a 10-year extrapolation of 1-year BPAR results sourced from paediatric RCTs or adult RCTs (where paediatric RCTs were not available). The addition of basiliximab and that of daclizumab to CAS was found to increase quality-adjusted life-years (QALYs) and decreased overall costs, a finding that was robust to sensitivity analyses. The incremental cost-effectiveness ratio (ICER) of replacing ciclosporin with tacrolimus was highly sensitive to the selection of the hazard ratio for graft loss from acute rejection, dialysis costs and the incorporation (or not) of side-effects. The ICERs for tacrolimus versus ciclosporin ranged from about 46,000 pounds/QALY to about 146,000 pounds/QALY. Although sensitive to varying the hazard ratio for graft loss with acute rejection, the ICER for replacing azathioprine with MMF remained in excess of 55,000 pounds/QALY. CONCLUSIONS: In general, compared with a regimen of ciclosporin, azathioprine and steroid, the newer immunosuppressive agents consistently reduced the incidence of short-term biopsy-proven acute rejection. However, evidence of the impact on side-effects, long-term graft loss, compliance and overall health-related quality of life is limited. Cost-effectiveness was estimated based on the relationship between short-term acute rejection levels from RCTs and long-term graft loss. Both the addition of daclizumab and that of basiliximab were found to be dominant strategies, that is, regarding cost savings and increased QALYs. The incremental cost-effectiveness of tacrolimus relative to ciclosporin was highly sensitive to key model parameter values and therefore may well be a cost-effective strategy. The incremental cost-effectiveness of MMF compared with azathioprine, although also sensitive to model parameter, was unattractive. There is a particular need for RCTs to assess the use of MMF, MPS and daclizumab for renal transplantation in children where no such evidence currently exists. Future comparative studies need to report not only on the impact of the newer immunosuppressants on short- and long-term clinical outcomes but also on side-effects, compliance, healthcare resource, costs and health-related quality of life.

Erythropoietin or darbepoetin for patients with cancer.

BACKGROUND: Anaemia associated with cancer and cancer therapy is an important clinical factor in the treatment of malignant diseases. Therapeutic alternatives are recombinant human erythropoietin (Epo), darbepoetin (Darbepo) and red blood cell transfusions. OBJECTIVES: The aim of this systematic review was to assess the effects of Epo or Darbepo to either prevent or treat anaemia in cancer patients. SEARCH STRATEGY: We searched the Central Register of Controlled Trials, MEDLINE and EMBASE and other data bases. Searches were done for the periods 01/1985 to 12/2001 for the first review and 1/2002 to 04/2005 for the update. We also contacted experts in the field and pharmaceutical companies. SELECTION CRITERIA: Randomised controlled trials on managing anaemia in cancer patients that compared the use of Epo/Darbepo (plus transfusion if needed) with observation until red blood cell transfusion was required. DATA COLLECTION AND ANALYSIS: Several reviewers independently assessed trial quality and extracted data. MAIN RESULTS: This update of the systematic review included a total of 57 trials with 9,353 patients. Of these, 27 trials with 3,287 adults were also included in the first Cochrane Review. Thirty trials with 6,066 patients were added during the update process. Use of Epo/Darbepo significantly reduced the relative risk of red blood cell transfusions (RR 0.64; 95% CI 0.60 to 0.68, 42 trials, n = 6,510). On average participants in the Epo/Darbepo group received one unit of blood less than the control group (WMD -1.05; 95% CI -1.32 to -0.78, 14 trials, n = 2,353). For participants with baseline haemoglobin below 12 g/dL haematological response was observed more often in participants receiving Epo/Darbepo (RR 3.43; 95% CI 3.07 to 3.84, 22 trials, n = 4,307). There was suggestive evidence that Epo/Darbepo may improve Quality of Life (QoL). The relative risk for thrombo embolic complications was increased in patients receiving Epo/Darbepo compared to controls (RR 1.67, 95% CI 1.35 to 2.06; 35 trials, n = 6,769). Uncertainties remain whether and how Epo/Darbepo effects tumour response (fixed effect RR 1.12; 95% CI 1.01 to 1.23, 13 trials, n = 2,833; random effects: RR 1.09; 95% CI 0.94 to 1.26) or overall survival (unadjusted and adjusted data: HR 1.08; 95% CI 0.99 to 1.18; 42 trials, n = 8,167). AUTHORS' CONCLUSIONS: There is consistent evidence that administration of Epo/Darbepo reduces the relative risk for blood transfusions and the number of units transfused in cancer patients. For patients with baseline haemoglobin below 12 g/dL (mild anaemia) there is strong evidence that Epo/Darbepo improves haematological response. There is suggestive evidence that Epo/Darbepo may improve QoL. However, there is strong evidence that Epo/Darbepo increases the relative risk for thrombo embolic complications. Whether and how Epo/Darbepo effects tumour response and overall survival remains uncertain.

The Effects of Different Aspirin Dosing Frequencies and the Timing of Aspirin Intake in Primary and Secondary Prevention of Cardiovascular Disease: A Systematic Review.

Enhancing the effectiveness of aspirin by tailoring administration regimens is an important question among health professionals. We conducted a systematic review to evaluate the evidence on the effects of different aspirin regimens in terms of timing (chronotherapy) or frequency of dosing in the prevention of cardiovascular disease. Only two out of the 28 included studies reported long-term cardiovascular outcomes, highlighting an evidence gap that future research should address. The remaining 26 studies used surrogate outcomes.

Patients' experiences of deep brain stimulation for Parkinson's disease: a qualitative systematic review and synthesis.

OBJECTIVE: To review and synthesise qualitative research studies that have explored patients' experience of deep brain stimulation (DBS) in advanced Parkinson's disease (PD). DESIGN: Systematic review and meta-synthesis of 7 original papers, using metaethnography. SETTING: Studies conducted in Denmark, France and Sweden. PARTICIPANTS: 116 patients who had undergone DBS and 9 spouses of patients. RESULTS: Prior to surgery, the experience of advancing PD is one of considerable loss and a feeling of loss of control. There are significant hopes for what DBS can bring. Following surgery, a sense of euphoria is described by many, although this does not persist and there is a need for significant transitions following this. We suggest that normality as a concept is core to the experience of DBS and that a sense of control may be a key condition for normality. Experience of DBS for patients and spouses, and of the transitions that they must undertake, is influenced by their hopes of what surgery will enable them to achieve, or regain (ie, a new normality). CONCLUSIONS: There is a need for further qualitative research to understand the nature of these transitions to inform how best patients and their spouses can be supported by healthcare professionals before, during and after DBS. In assessing the outcomes of DBS and other treatments in advanced PD, we should consider how to capture holistic concepts such as normality and control. Studies that examine the outcomes of DBS require longer term follow-up.

Epigenetic biomarkers in progression from non-dysplastic Barrett's oesophagus to oesophageal adenocarcinoma: a systematic review protocol.

INTRODUCTION: Barrett's oesophagus (BO), a metaplastic condition affecting the lower oesophagus due to long-standing gastro-oesophageal reflux and chronic inflammation, is a precursor lesion for oesophageal adenocarcinoma (OADC). There is no clinical test to predict which patients with BO will progress to OADC. The British Society of Gastroenterology recommends endoscopic surveillance of patients with BO. Epigenetic changes have been well characterised in the neoplastic progression of ulcerative colitis to colonic carcinoma, another gastrointestinal cancer associated with chronic inflammation. This systematic review protocol aims to identify and evaluate studies which examine epigenetic biomarkers in BO and their association with progression to OADC. METHODS AND ANALYSIS: All prospective and retrospective primary studies, and existing systematic reviews investigating epigenetic markers including DNA methylation, histone modification, chromatin remodelling, micro and non-coding RNAs of all types will be eligible for inclusion. Eligible patients are those over the age of 18 with BO, BO with dysplasia, OADC or unspecified oesophageal cancer. A comprehensive search of bibliographic databases using combinations of text and index words relating to the population, prognostic markers and outcome will be undertaken with no language restrictions. Results will be screened by 2 independent reviewers and data extracted using a standardised proforma. The quality and risk of bias of individual studies will be assessed using the Quality in Prognostic Studies (QUIPS) tool. A narrative synthesis of all evidence will be performed with key findings tabulated. Meta-analysis will be considered where studies and reported outcomes are considered sufficiently homogeneous, both clinically and methodologically. Findings will be interpreted in the context of the quality of included studies. The systematic review will be reported according to PRISMA guidelines. ETHICS AND DISSEMINATION: This is a systematic review of completed studies and no ethical approval is required. Findings from the full systematic review will be submitted for publication and presentation at national and international conferences which will inform future research on risk stratification in patients with BO. REVIEW REGISTRATION NUMBER: CRD42016038654.

The effectiveness and cost-effectiveness of parent training/education programmes for the treatment of conduct disorder, including oppositional defiant disorder, in children.

OBJECTIVES: To assess the clinical and cost-effectiveness of parent training programmes for the treatment of children with conduct disorder (CD) up to the age of 18 years. DATA SOURCES: Electronic databases. REVIEW METHODS: For the effectiveness review, relevant studies were identified and evaluated. A quantitative synthesis of behavioural outcomes across trials was also undertaken using two approaches: vote counting and meta-analysis. The economic analysis consisted of reviewing previous economic/cost evaluations of parent training/education programmes and the economic information within sponsor's submissions; carrying out a detailed exploration of costs of parent training/education programmes; and a de novo modelling assessment of the cost-effectiveness of parent training/education programmes. The potential budget impact to the health service of implementing such programmes was also considered. RESULTS: Many of the 37 randomised controlled trials that met the review inclusion and exclusion criteria were assessed as being of poor methodological quality. Studies were clinically heterogeneous in terms of the population, type of parent training/education programme and content, setting, delivery, length and child behaviour outcomes used. Both vote counting and meta-analysis revealed a consistent trend across all studies towards short-term effectiveness (up to 4 months) of parent training/education programmes (compared with control) as measured by a change in child behaviour. Pooled estimates showed a statistically significant improvement on the Eyberg Child Behaviour Inventory frequency and intensity scales, the Dyadic Parent-Child Interaction Coding System and the Child Behaviour Checklist. No studies reported a statistically significant result favouring control over parent training/education programmes. There were few statistically significant differences between different parent training/education programmes, although there was a trend towards more intensive interventions (e.g. longer contact hours, additional child involvement) being more effective. The cost of treating CD is high, with costs incurred by many agencies. A recent study suggested that by age 28, costs for individuals with CD were around 10 times higher than for those with no problems, with a mean cost of 70,019 pounds sterling. Criminality incurs the greatest cost, followed by educational provision, foster and residential care and state benefits. Only a small proportion of these costs fall on health services. Using a 'bottom-up' costing approach, the costs per family of providing parent training/education programmes range from 629 pounds sterling to 3839 pounds sterling depending on the type and style of delivery. Using the conservative assumption that there are no cost savings from treatment, a total lifetime quality of life gain of 0.1 would give a cost per quality-adjusted life-year of between 38,393 pounds sterling and 6288 pounds sterling depending on the type of programme delivery and setting. CONCLUSIONS: Parent training/education programmes appear to be an effective and potentially cost-effective therapy for children with CD. However, the relative effectiveness and cost-effectiveness of different models (such as therapy intensity and setting) require further investigation. Further research is required on the impact of parent training/education programmes on the quality of life of children with CD and their parents/carers, as well as on longer term child outcomes.

Batten disease and the ATP synthase subunit c turnover pathway: raising antibodies to subunit c.

Analysis of storage bodies in the ceroid-lipofuscinoses (Batten disease) has demonstrated a high protein content suggestive of a proteinosis. Direct N-terminal sequencing has shown that subunit c of mitochondrial ATP synthase is specifically stored in the disease in sheep and cattle, and in the human late infantile and juvenile diseases, as well as in 3 breeds of dogs. No differences have been found between the stored subunit c and that in normal mitochondria. No other mitochondrial components are stored. Different proteins, sphingolipid activator proteins (SAPs or saposins) A and D, are stored in the infantile disease. Linkage studies have shown that different forms of ceroid-lipofuscinosis are coded for on different genes on different chromosomes. The genes for subunit c, its production, its insertion into mitochondria, and mitochondrial function are normal. This suggests that underlying the various forms of the disease is a family of lesions in the normal pathway of subunit c turnover, after its normal insertion into the ATP synthase complex. Antibodies to subunit c offer one way of mapping that pathway and detecting the sites of lesions. Specific antibodies have been raised against stored subunit c, using a liposomal adjuvant system which proved superior to classical adjuvants. These antibodies are also useful diagnostically, both in Western blotting and in immunocytochemistry.

Immunocytochemical studies in the ceroid-lipofuscinoses (Batten disease) using antibodies to subunit c of mitochondrial ATP synthase.

Immunocytochemistry, using antibodies against subunit c of mitochondrial ATP synthase, has been carried out in the ovine, canine, late infantile, and adult forms of ceroid-lipofuscinosis. Intensity of staining varied depending on the particular disease, species, fixation regime, and the antibody used. Differential staining of storage cytosomes in neurons of affected sheep and those in the late infantile patient suggested exposure of different epitopes. This was supported by the variable staining using two different antibodies in ovine, late infantile, and adult onset (Kufs) diseases. Immunostaining of muscle in the late infantile, and muscle and ear cartilage in affected sheep can assist diagnosis but positive results may depend on the age of the patient, at least in the latter species. In these tissues there was immunostaining of structures not identified by histochemical or fluorescence microscopy in addition to storage cytosomes that could be identified by these means. Poor or no immunostaining occurred with canine tissues. At the ultrastructural level, storage cytosomes but not other organelles stained with the immunogold method.

Clinical effectiveness and cost-effectiveness of prehospital intravenous fluids in trauma patients.

OBJECTIVES: To systematically review the evidence on the effectiveness (in terms of mortality and morbidity) of prehospital intravenous (i.v.) fluid replacement, compared with no i.v. fluid replacement or delayed fluid replacement, in trauma patients with no head injury who have haemorrhage-induced hypotension due to trauma. DATA SOURCES: Electronic databases, relevant websites, handsearching, expert contacts. REVIEW METHODS: Search strategies were defined to identify randomised controlled trials (RCTs) and previous systematic reviews relating to the use of i.v. fluids in a prehospital (or other) setting compared to no fluids or delayed fluids. Inclusion and exclusion criteria were applied to identified studies, and key quality criteria of included studies were checked. Data were extracted independently by two reviewers. Economic evaluations were also systematically sought and appraised. RESULTS: Four relevant RCTs were identified, three of which were poorly designed and/or conducted. One good-quality RCT suggested that i.v. fluids may be harmful in patients with penetrating injuries. No evidence was found on the relative effectiveness of i.v. fluids in patients with blunt versus penetrating trauma. No reliable evidence was found from systematic reviews to suggest that a particular type of fluid is more beneficial compared to another type, although there was a trend favouring crystalloids over colloids. The relative costs of using i.v. fluids versus not using them were found to be very similar and changes in the use of fluids would therefore have no cost consequences for the ambulance service. A more detailed cost-effectiveness analysis would require further information on the relative consequences (mortality, morbidity) of different resuscitation strategies. CONCLUSIONS: The review found no evidence to suggest that prehospital i.v. fluid resuscitation is beneficial, and some evidence that it may be harmful. This evidence is however not conclusive, particularly for blunt trauma. A UK Consensus Statement, and to a lesser extent the UK Joint Royal Colleges Ambulance Liaison Committee guidelines represent a more cautious approach to fluid management than previously advocated and are therefore consistent with the limited evidence base. Further research is required on hypotensive (cautious) resuscitation versus delayed or no fluid replacement, particularly in blunt trauma. There is also a need for an improvement in the quality of data collection and analysis of routinely collected ambulance call-out data.

Identification and assessment of ongoing trials in health technology assessment reviews.

OBJECTIVES: To assess the importance of ongoing trials in health technology assessment reviews (HTARs) for the National Institute for Clinical Excellence and to provide practical recommendations for identifying ongoing trials and assessing their possible impact. DATA SOURCES: Electronic databases. REVIEW METHODS: Ongoing trials (or trials in progress) were defined as any trials that have started but where the results are not yet available or only interim results are available for HTARs. This methodological review included: (1) an assessment of ongoing trials in HTARs completed by the end of August 2002, (2) a survey and assessment of trial registers and other sources of ongoing trials and (3) a summary and assessment of available methods for assessing the possible impacts of ongoing trials. RESULTS: The identification of ongoing trials is a common phenomenon in reviews of health technology assessment. Twenty-three of the 32 HTARs identified one or more ongoing trials and in eight of these the information on identified ongoing trials was not considered in the evidence synthesis and research recommendations. All but one HTAR that considered the potential impact of ongoing trials adopted a narrative approach. Trial registers and grey literature are important sources of information on ongoing trials. All 32 HTARs explicitly or implicitly searched for unpublished studies, and/or ongoing trials and/or grey literature and trial registers. The assessment of six commonly used trial registers suggested that most registers provided sufficient information for reviewers to decide the relevance of identified ongoing trials. However, it is sometimes extremely difficult to know whether ongoing trials identified from different sources (registers) are the same trials or belong to the same multicentre trials. The ISRCTN (the International Standard Randomised Controlled Trial Number) is the most reliable system but it has not been widely adopted. The qualitative assessment of ongoing trials compared major features of completed and ongoing trials, providing information about the possible impact of ongoing trials in terms of relevance, validity, reliability and generalisability. Quantitative methods to assess the impact of ongoing trials include cumulative meta-analysis related methods, fail-safe N, Bayesian data monitoring, and Bayesian interim predictions. The most useful method may be the Bayesian predictive probability, which estimates predictive probabilities for any possible values of treatment effect. A case study indicated that the appropriate use of quantitative methods would strengthen findings from narrative assessment of possible impact of ongoing trials. CONCLUSIONS: Identification of ongoing trials is common in HTARs. Searching for ongoing trials in effectiveness reviews should be more thorough and explicit. Conversely, primary researchers, in particular those working with in multicentre trials, should label ongoing trials more clearly, preferably by ISRCTN. Qualitative assessment of identified ongoing trials is crucial and informative. Available quantitative methods could be used to strengthen findings from narrative assessment, although further research and more empirical examples are required. Information from ongoing trials may contribute to syntheses of results, conclusions and recommendations for future research. Future research is suggested into the identification and assessment of ongoing trials in other systematic reviews of effectiveness of health care interventions; existing and new methods for incorporating information on ongoing trials; comparing estimated impacts with the actual results of ongoing trials; and to incorporate findings from the assessment of ongoing trials into decision models.

Mutational spectra of tamoxifen-induced mutations in the livers of lacI transgenic rats.

Tamoxifen, an important drug in breast cancer treatment, causes liver cancer in rats. The standard range of in vitro tests have failed to show that it causes DNA damage, but 32P-postlabelling and DNA-binding studies have shown that tamoxifen forms DNA adducts in rat liver. In 1995 a transgenic rat (Big Blue; Stratagene, La Jolla, CA) became available which harbours the bacterial lacI gene, thereby allowing the in vivo study of tamoxifen mutagenesis. Recently, we [Styles JA et al. (1996): Toxicologist 30; 161] showed that tamoxifen caused on increase in the mutation frequency at the lacI gene in these transgenic rats. In this study, we report on our preliminary analysis of the mutational spectra of 33 control and 38 tamoxifen-induced mutant lacI genes. Plasmid DNA containing the lacI gene was isolated from the mutant phages and its DNA sequence determined. In the control animal group, 81% of the mutant lacI genes were point mutations, whilst in the tamoxifen-treated group, 62% of the mutant lacI genes were point mutations. Of the tamoxifen-induced mutants, 43% were GC-->TA transversions and 70% of point mutations. In the control group, GC-->TA transversions were 19% of all mutations and 24% of point mutations. Thus, compared with control animals, tamoxifen treatment had significantly increased the proportion of GC-->TA transversions.

Transmission of light across the adult and neonatal eyelid in vivo.

Light transmission characteristics of the human adult and neonatal eyelid were measured in vivo. Light was delivered via a grating monochromator through a fibre-optic mounted onto a contact lens placed under the eyelid, and detected using a photodiode on its external skin surface. Data from 5 adult and 9 preterm neonatal subjects indicate that the eyelid acts as a predominantly red-pass filter, with mean transmissions at 700 nm of 14.5% in the adult and 21.4% in the neonate, declining to less than or equal to 3% in both groups below 580 nm. The relevance of this data to clinical electrophysiology and to estimates of retinal irradiance is discussed.

ATP synthase activity in ovine ceroid lipofuscinosis [OCL6].

We measured ATP synthase activities in mitochondria isolated from livers of lambs with ceroid lipofuscinosis (OCL6) and compared them with those from similar isolations from obligate heterozygous and control lambs. Addition of excess Ca2+ to the incubation mixture resulted in an up-regulation of activity in mitochondria from control lambs but down-regulation in those from OCL6 affected lambs. The mean change in activity with Ca2+ for heterozygous animals was midway between those from control and affected groups being significantly different from control but not from affected. The change in ATP synthase activity to added Ca2+ was also measured in isolated mitochondria from affected and control lambs from 3 days to 25 months of age. As above, there was down-regulation to the addition of Ca2+ in affected lambs. There was a fall in percentage change to Ca2+ with age in both affected and control lambs. This was not significantly different in affected lambs indicating it was not associated with the stage of disease. The above in vitro results, if extrapolated to neurons in vivo, imply a potential dysfunction of mitochondria in OCL6 lambs that could lead to calcium mediated neurotoxicity and neuron death due to production of free radicals as implicit in the energy-linked excitotoxic hypothesis.