Barriers and facilitators for surgical site infection surveillance for adult cardiac surgery in a high-income setting: an in-depth exploration

BACKGROUND

Surgical site infection (SSI) surveillance aims to facilitate a reduction in SSIs through identifying infection rates, benchmarking, triggering clinical review and instituting infection control measures. Participation in surveillance is, however, variable suggesting opportunities to improve wider adoption.

AIM

To gain an in-depth understanding of the barriers and facilitators for SSI surveillance in a high-income European setting.

METHODS

Key informant interviews with 16 surveillance staff, infection prevention staff, nurses and surgeons from nine cardiac hospitals in England. Data were analysed thematically.

FINDINGS

SSI surveillance was reported to be resource intensive. Barriers to surveillance included challenges associated with data collection: data being located in numerous places, multiple SSI data reporting schemes, difficulty in finding denominator data, lack of interface between computerized systems, 'labour intensive' or 'antiquated' methods to collect data (e.g., using postal systems for patient questionnaires). Additional reported concerns included: relevance of definitions, perceived variability in data reporting, lack of surgeon engagement, unsupportive managers, low priority of SSIs among staff, and a 'blame culture' around high SSI rates. Facilitators were increased resources, better use of digital technologies (e.g., remote digital wound monitoring), integrating surveillance within routine clinical work, having champions, mandating surveillance, ensuring a closer relationship between surveillance and improved patient outcomes, increasing the focus on post-discharge surveillance, and integration with primary care data.

CONCLUSION

Using novel interviews with 'front-line' staff, identified opportunities for improving participation in SSI surveillance. Translating these findings into action will increase surveillance activity and bring patient safety benefits to a larger pool of surgical patients.

Systematic review of interventions for the prevention and treatment of postoperative urinary retention

Background

Postoperative urinary retention (PO‐UR) is an acute and painful inability to void after surgery that can lead to complications and delayed hospital discharge. Standard treatment with a urinary catheter is associated with a risk of infection and can be distressing, undignified and uncomfortable. This systematic review aimed to identify effective interventions for the prevention and treatment of PO‐UR that might be alternatives to urinary catheterization.

Methods

Electronic databases were searched from inception to September 2017. Randomized trials of interventions for the prevention or treatment of PO‐UR were eligible for inclusion. Studies were assessed for risk of bias using the Cochrane (2.0) tool. Two reviewers were involved at all review stages. Where possible, data were pooled using random‐effects meta‐analysis. The overall quality of the body of evidence was rated using the GRADE approach.

Results

Some 48 studies involving 5644 participants were included. Most interventions were pharmacological strategies to prevent PO‐UR. Based on GRADE, there was high‐certainty evidence to support replacing morphine in a regional anaesthetic regimen, using alpha‐blockers (number needed to treat to prevent one case of PO‐UR (NNT) 5, 95 per cent c.i. 5 to 7), the antispasmodic drug drotaverine (NNT 9, 7 to 30) and early postoperative mobilization (NNT 5, 4 to 8) for prevention, and employing hot packs or gauze soaked in warm water for treatment (NNT 2, 2 to 4). Very few studies reported on secondary outcomes of pain, incidence of urinary tract infection or duration of hospital stay.

Conclusion

Promising interventions exist for PO‐UR, but they need to be evaluated in randomized trials investigating comparative clinical and cost effectiveness, and acceptability to patients.

Early Warning Scores do not accurately predict mortality in sepsis: A meta-analysis and systematic review of the literature

OBJECTIVES

Early Warning Scores are used to evaluate patients in many hospital settings. It is not clear if these are accurate in predicting mortality in sepsis. We performed a systematic review and meta-analysis of multiple studies in sepsis. Our aim was to estimate the accuracy of EWS for mortality in this setting.

METHODS

PubMED, CINAHL, Cochrane, Web of Science and EMBASE were searched to October 2016. Studies of adults with sepsis who had EWS calculated using any appropriate tool (e.g. NEWS, MEWS) were eligible for inclusion. Study quality was assessed using QUADAS-2. Summary estimates were derived using HSROC analysis.

RESULTS

Six studies (4298 participants) were included. Results suggest that EWS cannot be used to predict which patients with sepsis will (positive likelihood ratio 1.79, 95% CI 1.53 to 2.11) or will not die (negative likelihood ratio 0.59, 95% CI 0.45 to 0.78). Two studies were rated as low risk of bias and one as unclear risk of bias on all domains. The other three studies were judged at high risk of bias in one domain.

CONCLUSION

Early Warning Scores are not sufficiently accurate to rule in or rule out mortality in patients with sepsis, based on the evidence available, which is generally poor quality.

Standardizing and monitoring the delivery of surgical interventions in randomized clinical trials

Background

The complexity of surgical interventions has major implications for the design of RCTs. Trials need to consider how and whether to standardize interventions so that, if successful, they can be implemented in practice. Although guidance exists for standardizing non‐pharmaceutical interventions in RCTs, their application to surgery is unclear. This study reports new methods for standardizing the delivery of surgical interventions in RCTs.

Methods

Descriptions of 160 surgical interventions in existing trial reports and protocols were identified. Initially, ten reports were scrutinized in detail using a modified framework approach for the analysis of qualitative data, which informed the development of a preliminary typology. The typology was amended with iterative sequential application to all interventions. Further testing was undertaken within ongoing multicentre RCTs.

Results

The typology has three parts. Initially, the overall technical purpose of the intervention is described (exploration, resection and/or reconstruction) in order to establish its constituent components and steps. This detailed description of the intervention is then used to establish whether and how each component and step should be standardized, and the standards documented within the trial protocol. Finally, the typology provides a framework for monitoring the agreed intervention standards during the RCT. Pilot testing within ongoing RCTs enabled standardization of the interventions to be agreed, and case report forms developed to capture deviations from these standards.

Conclusion

The typology provides a framework for use during trial design to standardize the delivery of surgical interventions and document these details within protocols. Application of this typology to future RCTs may clarify details of the interventions under evaluation and help successful interventions to be implemented.

Design a perfect study

Systematic review of intervention design and delivery in pragmatic and explanatory surgical randomized clinical trials

BACKGROUND

Surgical interventions are complex, with multiple components that require consideration in trial reporting. This review examines the reporting of details of surgical interventions in randomized clinical trials (RCTs) within the context of explanatory and pragmatic study designs.

METHODS

Systematic searches identified RCTs of surgical interventions published in 2010 and 2011. Included studies were categorized as predominantly explanatory or pragmatic. The extent of intervention details in the reports were compared with the CONSORT statement for reporting trials of non-pharmacological treatments (CONSORT-NPT). CONSORT-NPT recommends reporting the descriptions of surgical interventions, whether they were standardized and adhered to (items 4a, 4b and 4c). Reporting of the context of intervention delivery (items 3 and 15) and operator expertise (item 15) were assessed.

RESULTS

Of 4541 abstracts and 131 full-text articles, 80 were included (of which 39 were classified as predominantly pragmatic), reporting 160 interventions. Descriptions of 129 interventions (80.6 per cent) were provided. Standardization was mentioned for 47 (29.4 per cent) of the 160 interventions, and 22 articles (28 per cent) reported measurement of adherence to at least one aspect of the intervention. Seventy-one papers (89 per cent) provided some information about context. For one-third of interventions (55, 34.4 per cent), some data were provided regarding the expertise of personnel involved. Reporting standards were similar in trials classified as pragmatic or explanatory.

CONCLUSION

The lack of detail in trial reports about surgical interventions creates difficulties in understanding which operations were actually evaluated. Methods for designing and reporting surgical interventions in RCTs, contributing to the quality of the overall study design, are required. This should allow better implementation of trial results into practice.

The diagnostic utility and cost-effectiveness of selective nerve root blocks in patients considered for lumbar decompression surgery: a systematic review and economic model

BACKGROUND

Diagnostic selective nerve root block (SNRB) involves injection of local anaesthetic, sometimes in conjunction with corticosteroids, around spinal nerves. It is used to identify symptomatic nerve roots in patients with probable radicular pain that is not fully concordant with imaging findings.

OBJECTIVES

(1) Determine the diagnostic accuracy of SNRB in patients with low back and radiating pain in a lower limb; (2) evaluate whether or not accuracy varies by patient subgroups; (3) review injection-related adverse events; and (4) evaluate the cost-effectiveness of SNRB.

DATA SOURCES

MEDLINE, EMBASE, Science Citation Index, Bioscience Information Service (BIOSIS), Latin American and Caribbean Health Sciences Literature (LILACS) and grey literature databases were searched from inception to August 2011. Reference lists of included studies were screened.

METHODS

A systematic review (SR) of studies that assessed the accuracy of SNRB or adverse events in patients with low back pain and symptoms in a lower limb for the diagnosis of lumbar radiculopathy. Study quality was assessed using the quality assessment of diagnostic accuracy studies (QUADAS)-2 checklist. We used random-effects meta-analysis to pool diagnostic accuracy data. Decision tree and Markov models were developed, combining SR results with information on the costs and outcomes of surgical and non-surgical care. Uncertainty was assessed using probabilistic and deterministic sensitivity analyses.

RESULTS

Five studies assessed diagnostic accuracy: three diagnostic cohort and two within-patient case-control studies. All were judged to be at high risk of bias and had high concerns regarding applicability. In individual studies, sensitivity ranged from 57% [95% confidence interval (CI) 43% to 70%] to 100% (95% CI 76% to 100%) and specificity from 9.5% (95% CI 1% to 30%) to 86% (95% CI 76% to 93%). The most reliable estimate was judged to come from two cohort studies that used post-surgery outcome as the reference standard; summary sensitivity and specificity were 93% (95% CI 86% to 97%) and 26% (95% CI 5% to 68%), respectively. No study provided sufficient detail to judge whether or not accuracy varied by patient subgroup. Seven studies assessed adverse events. There were no major or permanent complications; minor complications were reported in 0-6% of patients. The addition of SNRB to the diagnostic work-up was not cost-effective with an incremental cost per quality-adjusted life-year of £1,576,007. Sensitivity analyses confirmed that SNRB was unlikely to be a cost-effective method for diagnosis and planning surgical therapy.

LIMITATIONS

We identified very few studies; all were at high risk of bias. The conduct and interpretation of SNRBs varied and there was no gold standard for diagnosis. Limited information about the impact of SNRB on subsequent care and the long-term costs and benefits of surgery increased uncertainty about cost-effectiveness.

CONCLUSIONS

There were few studies that estimated the diagnostic accuracy of SNRB in patients with radiculopathy and all were limited by the difficulty of making a reference standard diagnosis. Summary estimates suggest that specificity is low, but results are based on a small number of studies at a high risk of bias. Based on current weak evidence, it is unlikely that SNRB is a cost-effective method for identifying the symptomatic nerve root prior to lumbar spine surgery. Future research should focus on randomised controlled trials to evaluate whether or not SNRB improves patient outcomes at acceptable cost.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Colour vision testing for diabetic retinopathy: a systematic review of diagnostic accuracy and economic evaluation

OBJECTIVE

To determine the diagnostic performance and cost-effectiveness of colour vision testing (CVT) to identify and monitor the progression of diabetic retinopathy (DR).

DATA SOURCES

Major electronic databases including MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Database of Systematic Reviews were searched from inception to September 2008.

REVIEW METHODS

A systematic review of the evidence was carried out according to standard methods. An online survey of National Screening Programme for Diabetic Retinopathy (NSPDR) clinical leads and programme managers assessed the diagnostic tools used routinely by local centres and their views on future research priorities. A decision tree and Markov model was developed to estimate the incremental costs and effects of adding CVT to the current NSPDR.

RESULTS

In total, 25 studies on CVT met the inclusion criteria for the review, including 18 presenting 2 x 2 diagnostic accuracy data. The quality of studies and reporting was generally poor. Automated or computerised CVTs reported variable sensitivities (63-97%) and specificities (71-95%). One study reported good diagnostic accuracy estimates for computerised CVT plus retinal photography for detection of sight-threatening DR, but it included few cases of retinopathy in total. Results for pseudoisochromatic plates, anomaloscopes and colour arrangement tests were largely inadequate for DR screening, with Youden indices (sensitivity + specificity - 100%) close to zero. No studies were located that addressed patient preferences relating to CVT for DR. Retinal photography is universally employed as the primary method for retinal screening by centres responding to the online survey; none used CVT. The review of the economic evaluation literature found no previous studies describing the cost and effects of any type of CVT. Our economic evaluation suggested that adding CVT to the current national screening programme could be cost-effective if it adequately increases sensitivity and is relatively inexpensive. The deterministic base-case analysis indicated that the cost per quality-adjusted life-year gained may be 6364 pounds and 12,432 pounds for type 1 and type 2 diabetes respectively. However, probabilistic sensitivity analysis highlighted the substantial probability that CVT is not diagnostically accurate enough to be either an effective or a cost-effective addition to current screening methods. The results of the economic model should be treated with caution as the model is based on only one small study.

CONCLUSIONS

There is insufficient evidence to support the use of CVT alone, or in combination with retinal photography, as a method for screening for retinopathy in patients with diabetes. Better quality diagnostic accuracy studies directly comparing the incremental value of CVT in addition to retinal photography are needed before drawing conclusions on cost-effectiveness. The most frequently cited preference for future research was the use of optical coherence tomography for the detection of clinically significant macular oedema.

Successful immunotherapy of HCMV disease using virus-specific T cells expanded from an allogeneic stem cell transplant recipient

Opportunistic infection remains the principal cause of mortality in allogeneic stem cell transplant recipients with active extensive chronic graft-versus-host disease. Human cytomegalovirus (HCMV) represents an important cause of disease in this setting and the toxicity of protracted and recurrent antiviral treatment together with eventual drug resistance represents a significant limitation to therapy. Although the expansion and adoptive transfer of HCMV-specific T cells from the healthy original donor can be an effective strategy to control viral replication, this is not possible when donors are seronegative or are subsequently inaccessible. Here we demonstrate for the first time, the successful expansion of HCMV-specific T cells from a seropositive transplant recipient of a seronegative graft with active HCMV disease and the long-term reconstitution of protective antiviral immunity following their adoptive transfer back into the patient.

Acute Airway Obstruction Secondary to Achalasia Mega-oesophagus

Acute airway obstruction is a very rare presentation of achalasia. We report the case of a 78-year-old woman with previously undiagnosed achalasia who presented with acute respiratory distress and stridor due to tracheal compression by mega-oesophagus. Anaesthetists and physicians caring for patients with achalasia must be aware of the need for emergency oesophageal decompression in this rare and life-threatening condition.

Structural and functional heterogeneity of nicotinic receptors

Three gene families of the ligand-gated ion channel gene superfamily encode proteins which bind cholinergic ligands: (1) nicotinic acetylcholine receptors (AChRs) from skeletal muscle, (2) AChRs from neurons, and (3) neuronal alpha-bungarotoxin-binding proteins (alpha BgtBPs). AChRs from muscles and nerves function as ACh-gated cation channels, but alpha BgtBPs do not appear to function in this way. A family of neuronal AChR subtypes has been characterized using monoclonal antibodies and cDNA probes. Neuronal AChRs exhibit sequence homologies with muscle AChRs, but differ in subunit composition, pharmacological and electrophysiological properties, and, in some cases, apparent functional roles. The genes that encode the subunits of the various purified AChR subtypes have been determined in several cases. Histological localization of AChR subunit mRNAs by in situ hybridization and of subunit proteins by immunohistochemistry is being conducted with increasing resolution. The subunit structure of alpha BgtBP is uncertain, but cDNAs have been identified for two subunits. Sequences of these cDNAs reveal that alpha BgtBPs are members of the ligand-gated ion channel gene family, and suggest that they could function as gated cation channels. Biochemical and molecular genetic approaches to studies of neuronal AChRs and related proteins are merging to provide a detailed description of a complex family of AChRs widely dispersed throughout the nervous system, which are probably important to many activities of the nervous system, but whose functional roles are not yet well characterized.

Clinical effectiveness and cost-effectiveness of tests for the diagnosis and investigation of urinary tract infection in children: a systematic review and economic model

OBJECTIVES

To determine the diagnostic accuracy of tests for detecting urinary tract infection (UTI) in children under 5 years of age and to evaluate the effectiveness of tests used to investigate further children with confirmed UTI. Also, to evaluate the effectiveness of following up children with UTI and the cost-effectiveness of diagnostic and imaging tests for the diagnosis and follow-up of UTI in children under 5. An additional objective was to develop a preliminary diagnostic algorithm for healthcare professionals.

DATA SOURCES

Electronic databases were searched up to the end of 2002/early 2003. Consultation with experts in the field.

REVIEW METHODS

A systematic review was undertaken using published guidelines and results were analysed according to test grouping: diagnosis of UTI and further investigation of UTI. The cost-effectiveness results from existing evaluations were synthesised. A separate cost-effectiveness model was developed using the best available evidence, in part derived from the results of the systematic review, to illustrate the potential cost-effectiveness of some alternative management strategies in a UK setting. The results of the systematic review were used to propose diagnostic algorithms for the diagnosis and further investigation of UTI in children. Economic analyses did not contribute directly to the development of these algorithms.

RESULTS

The studies included in the review provided very little data on the accuracy of clinical investigations for the diagnosis of UTI, and criteria for clinical suspicion of UTI were not further defined. The majority of studies included in the review found that clean voided midstream urine (CVU) samples had similar accuracy to suprapubic aspiration (SPA) samples when cultured with the advantage of being a non-invasive collection method that can be used in the GP's surgery. Pad, nappy or bag specimens may be appropriate methods for obtaining a urine sample in non-toilet-trained children, although only limited data were available. Although the glucose test was reported to have the highest accuracy in terms of both ruling in and ruling out disease, only a limited number of studies of this test were included and these were conducted over 30 years ago. Dipstick tests are easy to perform in the GP's surgery, give an immediate result and are relatively cheap. The results of the systematic review showed that a dipstick for leucocyte esterase (LE) and nitrite, where both test results are interpreted in combination, was a good test both for ruling in (both positive) and ruling out (both negative) a UTI. A dipstick positive for either LE or nitrite and negative for the other provides inconclusive diagnostic information and further testing is therefore required in these patients. Microscopy is more time consuming and expensive to perform than a dipstick test, but potentially quicker and cheaper than culture. As with dipstick tests, a combination of microscopy for pyuria and bacteriuria can be used accurately to rule in and rule out a UTI. An indeterminate test result is again obtained if microscopy is positive for either pyuria or bacteriuria, and negative for the other. Confirmatory culture is required in these patients. In patients considered to have a UTI, further culture to determine antibiotic sensitivities may be an option to inform treatment decisions. Only one study satisfied the inclusion criteria of the economic review and the review highlighted a number of potential limitations of this study for NHS decision-making. A separate decision-analytic model was therefore developed to provide a more reliable estimate of the optimal strategy regarding the diagnosis and further investigation of children under 5 with suspected UTI from the perspective of the NHS. The economic model found that the optimal diagnostic strategy for children presenting with symptoms suggestive of UTI depends on a number of key factors. These included the relevant subgroup of children concerned, in terms of gender and age, and the health service's maximum willingness to pay for an additional quality-adjusted life-year.

CONCLUSIONS

The results of the systematic review were used to derive an algorithm for the diagnosis of UTI in children under 5. This algorithm represents the conclusions of the review in terms of effective practice. There were insufficient data to propose an algorithm for the further investigation of UTI in children under 5. The quality assessment highlighted several areas that could be improved upon in future diagnostic accuracy studies.

A systematic review of the effectiveness and cost-effectiveness of neuroimaging assessments used to visualise the seizure focus in people with refractory epilepsy being considered for surgery

OBJECTIVE

To review the effectiveness and/or accuracy, cost-effectiveness, and predictive value of neuroimaging of the cerebral cortex to visualise the seizure focus in people with refractory epilepsy being considered for surgery.

DATA SOURCES

Electronic databases, Internet searches, hand searching and consultation with experts.

METHODS

A systematic review was undertaken according to published guidelines. Results of diagnostic accuracy studies were analysed according to the imaging test evaluated. For each study the proportion of patients who were correctly localised, not localised, partially localised or incorrectly localised by the index test was calculated. Due to the heterogeneity present between studies, statistical pooling was not performed. Instead, a narrative synthesis of results is presented. For studies using multivariate analysis to look at the association of neuroimaging findings and outcome following surgery, all factors considered in the analyses were presented. Studies were grouped according to the neuroimaging technique investigated and the findings discussed with reference to possible sources of heterogeneity between studies.

RESULTS

No randomised controlled trials (RCTs) were identified, with the majority of studies evaluating the diagnostic accuracy of various imaging techniques in the localisation of epileptic seizure foci. There was significant heterogeneity (p<0.05) between studies for at least one of the localisation categories (correctly localised, not localised, partially localised and incorrectly localised) for all imaging techniques. Possible explanations for this heterogeneity include differing study designs, index test characteristics, reference standards and population characteristics. Test performance was more promising in studies restricted to patients with temporal lobe epilepsy. Ictal single photon emission computed tomography (SPECT) generally had more correctly localising (70--100%) and fewer non-localising (0--7%) scans than other techniques evaluated in patients with temporal lobe epilepsy. Results for computed tomography and interictal SPECT suggest that these tests are relatively poor at localising the seizure focus. Volumeric magnetic resonance imaging (MRI) and position emission tomography (PET) appear promising, and subtraction ictal single photon emission computed tomography co-registered to magnetic resonance imaging (SISCOM) and magnetic resonance spectrosopy (MRS) less promising than ictal SPECT, but these technologies have been assessed in fewer studies. T2 relaxometry was reported in only one small study with inconclusive results. Seventeen studies (33 evaluations) provided sufficient data on the association of a localised scan with outcome following surgery to calculate a relative risk. The majority of evaluations (24/33) suggested that patients with a correctly or partially localised scan had a better outcome following surgery than those with an incorrectly localised or non-localised scan. However, this association was statistically significant in only three studies, two evaluating routine MRI [(relative risk (RR) 2.74, 95% confidence interval (CI): 1.32 to 5.67; RR 1.28, 95% CI: 1.00 to 1.63] and the other SISCOM (RR 2.12, 95% CI: 1.01, 4.44). Nine studies used multivariate analysis to investigate the association of MRI (7 studies), MRS and volumetric MRI (1 study), PET (3 studies), SPECT (1 study) and SISCOM (3 studies) with the outcome following surgery. There was a trend for localisation of abnormalities to be associated with a beneficial outcome.

CONCLUSIONS

Due to the limitations of the included studies, the results of this review do little to inform clinical practice, with insufficient evidence regarding effectiveness and cost-effectiveness of imaging techniques in the work-up for epilepsy surgery. Given the inadequacy of existing data, there is a pressing need for studies investigating the utility of imaging techniques in the work up for epilepsy surgery. The most reliable method to achieve this is the RCT, which could examine the single tests or combinations of tests on patient outcome. The authors suggest that it is important that clinicians, patient groups, policy makers and healthcare/research funders meet and debate the most appropriate way to investigate these technologies.

Epidural analgesia for acute symphysis pubis dysfunction in the second trimester

We report a case of severe symphysis pubis dysfunction in a parturient during her second trimester of a twin pregnancy. Symphysis pubis dysfunction produces pain, instability and limitation of mobility and function, of the symphysis pubis during pregnancy and labour. It is often under-treated. We provided lumbar epidural analgesia with intermittent top-ups of bupivacaine 0.1% with fentanyl 2 micrograms/mL for 72 h. This provided initial analgesia, breaking a vicious cycle of pain and muscle spasm. The benefits extended into the remainder of her pregnancy. Subsequently, simple analgesics and physiotherapy allowed control of pain until vaginal delivery 15 weeks later.

Development and validation of methods for assessing the quality of diagnostic accuracy studies

OBJECTIVES

To develop a quality assessment tool which will be used in systematic reviews to assess the quality of primary studies of diagnostic accuracy.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, BIOSIS and the methodological databases of both CRD and the Cochrane Collaboration.

REVIEW METHODS

Three systematic reviews were conducted to provide an evidence base for the development of the quality assessment tool. A Delphi procedure was used to develop the quality assessment tool and the information provided by the reviews was incorporated into this. A panel of nine experts in the area of diagnostic accuracy studies took part in the Delphi procedure to agree on the items to be included in the tool. Panel members were also asked to provide feedback on various other items and whether they would like to see the development of additional topic and design specific items. The Delphi procedure produced the quality assessment tool, named the QUADAS tool, which consisted of 14 items. A background document was produced describing each item included in the tool and how each of the items should be scored.

RESULTS

The reviews produced 28 possible items for inclusion in the quality assessment tool. It was found that the sources of bias supported by the most empirical evidence were variation by clinical and demographic subgroups, disease prevalence/severity, partial verification bias, clinical review bias and observer/instrument variation. There was also some evidence of bias for the effects of distorted selection of participants, absent or inappropriate reference standard, differential verification bias and review bias. The evidence for the effects of other sources of bias was insufficient to draw conclusions. The third review found that only one item, the avoidance of review bias, was included in more than 75% of tools. Spectrum composition, population recruitment, absent or inappropriate reference standard and verification bias were each included in 50-75% of tools. Other items were included in less than 50% of tools. The second review found that the quality assessment tool should have the potential to be discussed narratively, reported in a tabular summary, used as recommendations for future research, used to conduct sensitivity or regression analyses and used as criteria for inclusion in the review or a primary analysis. This suggested that some distinction is needed between high- and low-quality studies. Component analysis was considered the best approach to incorporate quality into systematic reviews of diagnostic studies and this was taken into consideration when developing the tool.

CONCLUSIONS

This project produced an evidence-based quality assessment tool to be used in systematic reviews of diagnostic accuracy studies. Through the various stages of the project the current lack of such a tool and the need for a systematically developed validated tool were demonstrated. Further work to validate the tool continues beyond the scope of this project. The further development of the tool by the addition of design- and topic-specific criteria is proposed.

Assembly of N-methyl-D-aspartate (NMDA) receptors

The N-methyl-D-aspartate receptor (NMDAR) requires both NR1 and NR2 subunits to form a functional ion channel. Despite the recent advances in our understanding of the contributions of these different subunits to both the function and pharmacology of the NMDAR, the precise subunit stoichiometry of the receptor and the regions of the subunits governing subunit interactions remain unclear. Since NR2 subunits are not transported to the cell surface unless they associate with NR1 subunits, cell-surface expression of NR2A can be used to monitor the association of the different subunits in cells transfected with N- and C-terminally truncated NR1 subunits. By combining measurements of cell-surface expression of NR2A with co-immunoprecipitation experiments, and by using Blue Native gel electrophoresis to determine the oligomerization status of the subunits, we have shown that regions of the N-terminus of NR1 are critical for subunit association, whereas the truncation of the C-terminus of NR1 before the last transmembrane region has no effect on the association of the subunits. Evidence from the Blue Native gels, sucrose-gradient centrifugation and size exclusion of soluble NR1 domains suggests that NR1 subunits alone can form stable dimers. Using a cell line, which can be induced to express the NMDAR following exposure to dexamethasone, we have shown that NMDARs can be expressed at the cell surface within 5 h of the recombinant gene induction, and that there appears to be a delay between the first appearance of the subunits and their stable association.

Liver transplantation for HCV-associated liver cirrhosis: predictors of outcomes in a population with significant genotype 3 and 4 distribution

End-stage liver disease associated with hepatitis C virus (HCV) infection is now the leading indication for liver transplantation in adults. However, reinfection of the graft is universal. We aimed to determine predictors of outcome of HCV-liver transplant recipients in the Australian and New Zealand communities. The following variables were analysed: demographic factors, coexistent pathology at the time of transplantation, HCV genotype, and donor age. Outcomes measures were: 1. mortality; 2. development of HCV-related complications, which were stage 3 or 4 fibrosis, or mortality from HCV-related graft failure, or both. Between January 1989 and December 30, 1999, 182 patients were transplanted for HCV-associated cirrhosis. The median follow-up period was 4 years (range, 0 to 13 years). Genotype data were available on 157 patients. The distribution of genotypes among the 157 patients was as follows: 36 (23%) genotype 1a, 30 (19%) genotype 1b, 4 (9%) genotype 1, 17 (11%) genotype 2, 41 (26%) genotype 3a, and 16 (10%) genotype 4. Eight (5%) patients were HCV-polymerase chain reaction (PCR)-negative (but HCV-antibody-positive). Donor age and genotype 4 were associated with an increased risk of retransplantation or death (P <.001 and.05, respectively). Meanwhile, donor age, genotype 4, and pretransplant excess alcohol were risk factors for the development of HCV-related complications (P =.004,.008, and.02, respectively). In contrast, patients with genotype 3a were less likely to develop HCV-related complications (P =.05). In a population of HCV liver transplant recipients with a heterogeneous genotype distribution, donor age, and genotype 4, were predictors of a worse outcome, whereas genotype 3 was associated with a more favorable outcome.

Interventions for the treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis



 The research evidence on the effectiveness of interventions for the treatment and management of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) published in a recent issue of Effective Health Care is reviewed.

The York review--a systematic review of public water fluoridation: a commentary

Following the election of the British government in May 1997, a policy document outlining proposals to improve the health of the nation was published. This document placed a major emphasis on reducing inequalities in health and recognised the continuing poor state of oral health in deprived communities. However, whilst acknowledging the benefits of water fluoridation as a caries preventive measure, the Department of Health suggested that most of the research had been carried out some years ago and furthermore, recognised that strong views were held both for and against fluoridation.

Identification and quantitative analysis of the phytoecdysteroids in Silene species (Caryophyllaceae) by high-performance liquid chromatography. Novel ecdysteroids from S. pseudotites

Many species in the genus Silene (Caryophyllaceae) have previously been shown to contain ecdysteroids and this genus is recognised as a good source of novel ecdysteroid analogues. We have used ecdysteroid-specific radioimmunoassays and the microplate-based Drosophila melanogaster B(II) cell bioassay for ecdysteroid agonist and antagonist activities to identify further phytoecdysteroid-containing species in this genus. The main ecdysteroid components from 10 Silene species (S. antirrhina, S. chlorifolia, S. cretica, S. disticha, S. echinata, S. italica, S. portensis, S. pseudotites, S. radicosa, S. regia) were isolated and identified, mainly by normal-phase and reversed-phase high-performance liquid chromatography. The amount of each ecdysteroid was determined by comparing chromatogram peak areas with those for reference 20-hydroxyecdysone (20E) on reversed-phase HPLC. 20E is the most abundant ecdysteroid in each of the Silene extracts. Polypodine B, 2-deoxy-20-hydroxyecdysone and ecdysone are also common ecdysteroids in these Silene species, but the proportions of these ecdysteroids vary between the Silene species. HPLC proved to be a quick and effective way to screen Silene species, determine ecdysteroid profiles and, hence, identify extracts containing novel analogues. An extract of the aerial parts of S. pseudotites was found to contain several new ecdysteroids. These have been isolated and identified spectroscopically (by NMR and mass spectrometry) as 2-deoxyecdysone 22beta-D-glucoside, 2-deoxy-20,26-dihydroxyecdysone and 2-deoxypolypodine B 3beta-D-glucoside. Additionally, (5alpha-H)-2-deoxyintegristerone A (5alpha-2H 91%, 5alpha-1H 9%) was isolated as an artefact. This study contributes to the understanding of ecdysteroid distribution in Silene species and provides further information on the chemotaxonomic significance of ecdysteroids in Silene species.

Limnantheoside C (20-hydroxyecdysone 3-O-beta-D-glucopyranosyl-[1-->3]-beta-D-xylopyranoside), a phytoecdysteroid from seeds of Limnanthes alba (limnanthaceae)

A new ecdysteroid glycoside, limnantheoside C (20-hydroxyecdysone 3-O-beta-D-glucopyranosyl-[-->3]-beta-D-xylopyranoside [1]), together with limnantheoside A (20-hydroxyecdysone 3-O-beta-D-xylopyranoside [2]) and 20-hydroxyecdysone (3) have been isolated by bioassay/RIA-directed HPLC analyses of a methanol extract of the seedmeal of Limnanthes alba Hartw. ex Benth. The structure of the novel ecdysteroid glycoside (1) was determined unambiguously by UV, LSIMS and a combination of 1D- and 2D-NMR experiments. These three compounds are isolated from Limnanthes alba for the first time.

8-O-acetylharpagide is not an ecdysteroid agonist

We have reinvestigated the activity of 8-O-acetylharpagide, an iridoid glucoside, as an ecdysteroid agonist. Elbrecht et al. (Insect Biochem. Mol. Biol. 26 (1996) 519) isolated a preparation of this compound from Ajuga reptans L. and ascribed ecdysteroid agonist activity on the basis of the induction of an ecdysteroid-like response in Drosophila melanogaster KcO cells, the displacement of [3H]ponasterone A from the Drosophila receptor and the activation of an ecdysteroid-regulated gene in a transactivation assay. We provide evidence that the agonist activity derives from contaminating ecdysteroids; A. reptans is a species rich in ecdysteroids. Purified 8-O-acetylharpagide is not active in the D. melanogaster B(II) cell bioassay, neither as an agonist nor as an antagonist, nor does it displace [3H]ponasterone A from dipteran or lepidopteran ecdysteroid receptor complexes.

Phytoecdysteroids in seeds of Lloydia serotina (Liliaceae)

Seeds of a number of species in the Liliaceae (sensu Brummitt, 1992) were examined for the presence of ecdysteroid agonist and antagonist activities. No species were antagonistic to 20-hydroxyecdysone action on the ecdysteroid-responsive Drosophila melanogaster B(II) cell line and only one extract, that of Lloydia serotina, was agonistic. This activity is attributable to the presence of phytoecdysteroids as detected by ecdysteroid-specific radioimmunoassay and the agonist version of the B(II) bioassay. HPLC in conjunction with radioimmunoassay and bioassay have been used to determine the ecdysteroid profile. The major ecdysteroids present are identified as 20-hydroxyecdysone and polypodine B (5beta,20-dihydroxyecdysone).

Interventions for the treatment and management of chronic fatigue syndrome: a systematic review

CONTEXT

A variety of interventions have been used in the treatment and management of chronic fatigue syndrome (CFS). Currently, debate exists among health care professionals and patients about appropriate strategies for management.

OBJECTIVE

To assess the effectiveness of all interventions that have been evaluated for use in the treatment or management of CFS in adults or children.

DATA SOURCES

Nineteen specialist databases were searched from inception to either January or July 2000 for published or unpublished studies in any language. The search was updated through October 2000 using PubMed. Other sources included scanning citations, Internet searching, contacting experts, and online requests for articles.

STUDY SELECTION

Controlled trials (randomized or nonrandomized) that evaluated interventions in patients diagnosed as having CFS according to any criteria were included. Study inclusion was assessed independently by 2 reviewers. Of 350 studies initially identified, 44 met inclusion criteria, including 36 randomized controlled trials and 8 controlled trials.

DATA EXTRACTION

Data extraction was conducted by 1 reviewer and checked by a second. Validity assessment was carried out by 2 reviewers with disagreements resolved by consensus. A qualitative synthesis was carried out and studies were grouped according to type of intervention and outcomes assessed.

DATA SYNTHESIS

The number of participants included in each trial ranged from 12 to 326, with a total of 2801 participants included in the 44 trials combined. Across the studies, 38 different outcomes were evaluated using about 130 different scales or types of measurement. Studies were grouped into 6 different categories. In the behavioral category, graded exercise therapy and cognitive behavioral therapy showed positive results and also scored highly on the validity assessment. In the immunological category, both immunoglobulin and hydrocortisone showed some limited effects but, overall, the evidence was inconclusive. There was insufficient evidence about effectiveness in the other 4 categories (pharmacological, supplements, complementary/alternative, and other interventions).

CONCLUSIONS

Overall, the interventions demonstrated mixed results in terms of effectiveness. All conclusions about effectiveness should be considered together with the methodological inadequacies of the studies. Interventions which have shown promising results include cognitive behavioral therapy and graded exercise therapy. Further research into these and other treatments is required using standardized outcome measures.

Screening of environmental contaminants for ecdysteroid agonist and antagonist activity using the Drosophila melanogaster B(II) cell in vitro assay

The B(II) bioassay was developed as a rapid and reliable tool for detecting potential insect growth regulators acting as ecdysteroid receptor (ant)agonists. Based on an ecdysteroid-responsive cell line from Drosophila melanogaster, this microplate assay is ideally suited to the evaluation of environmental contaminants as potential endocrine disrupters. Data are presented for about 80 potential environmental contaminants, including industrial chemicals, pesticides, pharmaceuticals, phytoestrogens, and vertebrate steroids, and are compared with data for known (ant)agonists. Apart from androst-4-ene-3,17-dione (a weak antagonist), vertebrate steroids were inactive at concentrations up to 10(-3) M. The vast majority of xenobiotics also showed no (ant)agonist activity. Among the industrial chemicals, antagonistic activity was observed for bisphenol A median effective concentration (EC50) of 1.0 x 10(-4) M and diethylphthalate (EC50 of 2.0 x 10(-3) M). Some organochlorine compounds also showed weak antagonistic activity, including o,p'-dichlorodiphenyldichloroethylene (DDE), p,p'-DDE, dieldrin, and lindane (EC50 of 3.0 x 10(-5) M). For lindane, bisphenol A, and diethylphthalate, activity is not associated with impurities in the samples and, for lindane and bisphenol A at least, the compounds are able to compete with ecdysteroids for the ligand binding site on the receptor complex, albeit at concentrations very much higher than those found in the environment. The only pharmaceutical showing any detectable antagonist activity was 17alpha-ethynylestradiol. In the context of recent publications on potential endocrine disruption in marine and freshwater arthropods, these findings suggest that, for some compounds (e.g., diethylstilbestrol), ecdysteroid receptor-mediated responses are unlikely to be involved in producing chronic effects. The B(II) assay has a potentially valuable role to play in distinguishing between endocrine-mediated, which normally occur at submicromolar concentrations, and pharmacological effects in insects and crustaceans.

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)

On the distribution of phytoecdysteroids in plants

The occurrence and levels of phytoecdysteroids in the seeds and other parts of plants grown from the seeds of 180 randomly selected plant species were assessed and compared. Ecdysteroids are frequently detectable in leaves and flowers, but less so in stems, roots and seeds. The seeds of 290 species were assessed for the presence of hydrolysable ecdysteroid conjugates. Low levels of conjugates were detected in a significant number of species, large amounts being present only when levels of free ecdysteroids were high. Individual plants of Arabidopsis thaliana were assessed for the presence of phytoecdysteroids. While plants of this species are generally ecdysteroid negative, individual plants in the population accumulate low levels of ecdysteroids. Extracts of seeds of 50 "ecdysteroid-negative" species were concentrated and partially purified to determine if they possess ecdysteroids at levels below the usual detection levels. Ecdysteroids were detectable by radioimmunoassay in almost all of these concentrated samples. Thus, all lines of evidence point to the conclusion that all species of plants have the capacity to produce at least low levels of phytoecdysteroids. This has important implications for the protection of crop species through enhancing ecdysteroid levels by breeding/genetic modification strategies.

The ecdysteroid agonist/antagonist and brassinosteroid-like activities of synthetic brassinosteroid/ecdysteroid hybrid molecules

A series of synthetic hybrid brassinosteroid/ecdysteroid structures has been assessed for their ecdysteroid agonist/antagonist activities in the Drosophila melanogaster B(II) cell bioassay and for brassinosteroid-like activity in the rice lamina inclination test. Most of the compounds proved inactive for ecdysteroid agonist activity, demonstrating the specificity of the ecdysteroid receptor for compounds closely structurally related to 20-hydroxyecdysone. However, compound 18, with 14alpha-hydroxy-7-en-6-one and 22S-hydroxy functionalities (as in most active ecdysteroids), possessed distinct agonist activity (median effective concentration = 1.4 x 10(-5) M), although this is still almost 2000-fold less active than 20-hydroxyecdysone (25). Compounds 13 and 15 possessed weak agonist activity. Compounds 5, 11 and 14 weakly antagonised the action of 20-hydroxyecdysone (at 5 x 10(-8) M) on B(II) cells. In the brassinosteroid bioassay, most of the tested compounds showed activity. This may reflect the metabolic capability of plant tissue to convert test compounds to more active analogues. However, it is clear that biological activity declines as the structure of the test compound deviates further from that of castasterone (16). Three ecdysteroids (25, 26 and 27) are completely inactive in the rice lamina inclination test. These studies demonstrate the high specificities of the insect ecdysteroid receptor and the plant brassinosteroid receptor and indicate that phytoecdysteroids, even in high concentrations, would not interfere with brassinosteroid signalling pathways in plants where the two classes of compounds co-occur. Equally, brassinosteroids would not interfere with ecdysteroid signalling in insects, especially if one takes into account the low concentrations of brassinosteroids in the diet of phytophagous insects.

Identification of molecular determinants that are important in the assembly of N-methyl-D-aspartate receptors

To determine which domains of the N-methyl-d-aspartate (NMDA) receptor are important for the assembly of functional receptors, a number of N- and C-terminal truncations of the NR1a subunit have been produced. Truncations containing a complete ligand binding domain bound glycine antagonist and gave binding constants similar to those of the native subunit, suggesting they were folding to form antagonist binding sites. Since NR2A is not transported to the cell surface unless it is associated with NR1 (McIlhinney, R. A. J., Le Bourdellès, B., Tricuad, N., Molnar, E., Streit, P., and Whiting, P. J. (1998) Neuropharmacology 37, 1355-1367), surface expression of NR2A can be used to monitor the association of the subunits. There was progressive loss of NR2A cell surface expression as the N terminus of NR1a was shortened, with complete loss when truncated beyond residue 380. Removal of the C terminus and/or the last transmembrane domain did not affect NR2A surface expression. Similar results were obtained in co-immunoprecipitation experiments. The oligomerization status of the co-expressed NR1a constructs and NR2A subunits was investigated using a non-denaturing gel electrophoresis system (blue native-polyacrylamide gel electrophoresis) and sucrose density gradient centrifugation. The blue native-polyacrylamide gel electrophoresis system also showed that the NR1a subunits could form a homodimer, which was confirmed using soluble constructs of the NR1a subunit. Together these results suggest the residues N-terminal of residue 380 are important for the association of NR2A with NR1a and that the complete N-terminal domain of the NR1a subunit is required for oligomerization with NR2A.

Identification and ecdysteroid antagonist activity of three oligostilbenes from the seeds of Carex pendula (Cyperaceae)

Methanolic extracts of seeds of several (Carex species were found to antagonise the action of 20-hydroxyecdysone in the Drosophila melanogaster microplate-based B(II) cell bioassay. Bioassay-guided HPLC analysis of seeds of Carex pendula (drooping sedge) provided one previously unknown tetrastilbene (cis-miyabenol A) and two known oligostilbenes (kobophenol B and cis-miyabenol C) as the biologically active compounds (EC50 values were 31, 37 and 19 microM, respectively, vs. 5 x 10(-8) M 20-hydroxyecdysone). The structures and relative stereochemistries of these compounds were deduced by comprehensive ID- and 2D-NMR experiments. These compounds are isolated from Carex pendula for the first time. In vitro experiments with dipteran and lepidopteran ecdysteroid receptor proteins demonstrate that the oligostilbenes are able to compete with radiolabelled ecdysteroid ([3H]ponasterone A) for occupancy of the ligand binding site. IC50/Ki values are similar to the EC50 values obtained in the B(II) bioassay.

Ecdysteroids and bufadienolides from Helleborus torquatus (Ranunculaceae)

Three bufadienolides, hellebortin A (5-[beta-D-glucopyranosyloxy]-10,14,16-trihydroxy-19-nor-[5beta,10beta,14beta,16beta]-bufa-3,20,22-trienolide [1]), hellebortin B (5-[beta-D-glucopyranosyloxy]-3,4-epoxy-14-hydroxy-19-oxo-bufa-20,22-dienolide [2]) and hellebortin C (5-[beta-D-glucopyranosyloxy]-3,4-epoxy-10,14-dihydroxy-19-nor-bufa-20,22-dienolide [3]), together with 20-hydroxyecdysone 3-O-beta-D-glucoside (4) and 20-hydroxyecdysone (5) have been isolated by bioassay- and RIA-directed HPLC analyses of a methanol extract of the seeds of Helleborus torquatus. The structure and relative stereochemistry of the novel bufadienolide hellebortin A (1) and the structures of hellebortin B (2) and hellebortin C (3) were determined unambiguously by comprehensive analyses of their 1D and 2D NMR data. These five compounds are isolated from Hellborus torquatus for the first time. The biological activities of compound 1, 4 and 5 as ecdysteroid agonists and antagonists have been assessed.

Thy1 glomerulonephritis induced in young lewis rats accelerates age-related glomerulosclerosis

Age-related and disease-induced glomerulosclerosis (GS) in rats have both been well defined in a number of strains and experimental models, but the inter-relationship between the two is not clear. The present study was undertaken to compare the pattern of glomerular injury in these two types of GS. One- and two-shot Thy1 glomerulonephritis (GN) was induced at 2 months of age and followed for 12 months. At 12 months histological injury in proteinuric rats was characterized by segmental hyaline lesions. Two-shot Thy1 GN resulted in accelerated, but morphologically identical injury at 8 months. Histological lesions predictive of subsequent accelerated GS were evaluated at 1, 2, 4 and 6 months. In this regard, glomerular hypercellularity, rather than hypertrophy or matrix increase, was the most consistent histological index of later accelerated disease. The profibrotic cytokines transforming growth factor (TGF)-beta(1) and -beta(3) were localized distinctly to segmental hyaline lesions, but not to areas of matrix increase within the glomerular tuft. This study reveals that GS after Thy1 GN represents acceleration of an age-related disease, presents evidence for use of prolonged glomerular hypercellularity as the best histological index of future disease progression, and correlates the key lesion of GS in these animals, the segmental hyaline lesion, with the presence of TGF-beta peptides.

Phytoecdysteroids in the genus Asparagus (Asparagaceae)

Phytoecdysteroids, plant steroids which are analogues of invertebrate steroid hormones, probably contribute to the deterrence of phytophagous invertebrate predators. They also seem to possess antimicrobial activity and several pharmaceutical and medicinal benefits have been ascribed to them. Here. we present a survey of seeds of 16 species of the genus Asparagus (Asparagaceae), including the crop species A. officinalis, for ecdysteroid agonists (including phytoecdysteroids) and antagonists. Seven species were found to contain ecdysteroids with levels ranging from just detectable (A. racemosus and A. sarmentosus) to relatively high (A. laricinus). RP-HPLC/RIA/bioassay has been used to separate positive extracts of four species (A. falcatus, A. laricinus, A. ramosissimus and A. scandens) and analyse the ecdysteroid profiles. The identities of the major ecdysteroids were confirmed by NP-HPLC. Seeds of A. officinalis do not contain detectable levels of ecdysteroids, but leaves, stems and roots contain low levels (detectable by RIA). This indicates that A. officinalis retains the genetic capacity to synthesise ecdysteroids and that future strategies could be developed for enhanced protection of asparagus spears through elevated ecdysteroid levels.

Phytoecdysteroid profiles in seeds of Sida spp. (Malvaceae)

Procedures are presented for the assessment of the phytoecdysteroid profiles in small plant samples (ca. 25 mg), using seeds of Sida spp. as an example. The procedures are suitable for the analysis of minute or valuable samples and provide copious information for chemotaxonomic purposes. Methanolic extracts of the plant material, after partitioning against hexane, were separated by reversed-phase gradient HPLC monitored by PAD, RIA and bioassay. Aliquots of the fractions were also treated with Helix pomatia hydrolases, followed by RIA and bioassay, in order to assess the presence of hydrolysable ecdysteroid conjugates. Further information could also be obtained by separation of samples using normal-phase gradient HPLC. Among 11 species of Sida examined, seed extracts of S. acuta (= S. carpinifolia) and S. rhombifolia were found to contain significant amounts of ecdysteroids, seed extracts of S. filicaulis contained only moderate levels, whilst the remaining species showed no detectable levels of ecdysteroids. The ecdysteroid profiles of the extracts of the three positive species were significantly different, demonstrating that phytoecdysteroids have chemotaxonomic value in this genus.

Assessment of natural products in the Drosophila melanogaster B(II) cell bioassay for ecdysteroid agonist and antagonist activities

Ecdysteroid agonist and antagonist activities can be detected and quantified with the Drosophila melanogaster B(II) cell bioassay. This bioassay is convenient, sensitive and robust. We report the assessment with this bioassay of the activities of a wide range of compounds representing a number of classes of natural products. Many compounds were inactive over a wide concentration range (10(-8) to 10(-4) or 10(-3) M) or cytotoxic at high concentrations. However, antagonisitic activity was associated with several classes of compounds: cucurbitacins and withanolides (extending previous findings) and phenylalkanoids and certain alkaloids (described for the first time). A withanolide (withaperuvin D) is identified which possesses agonistic activity. Brassinosteroids, which have been ascribed (ant)agonistic properties in the past, were not found to be active in the B(II) bioassay, either as agonists or antagonists. Possible reasons for the prevalence of antagonists and for the low potency of the majority of them are discussed.

Ecdysteroid agonist and antagonist activities in species of the Solanaceae

Previously, it has been shown that certain withanolides from Iochroma gesnerioides (Solanaceae) possess ecdysteroid antagonistic activity. Phytoecdysteroids (agonists) are widely distributed in the plant world, but solanaceous species have not been extensively examined for their presence. We have now surveyed 128 species of solanaceous plants for the presence of ecdysteroid agonist and antagonist activities using the Drosophila melanogaster B(II) cell line bioassay. Only weak antagonistic activity was associated with a few of the methanolic extracts, including those from species known to contain high levels of withanolides. Therefore, the major withanolides are inactive per se, but they may be activated after ingestion by invertebrate predators. Several extracts possessed ecdysteroid agonist activity as a consequence of the presence of phytoecdysteroids. Phytoecdysteroid-accumulating species are at least as common in the Solanaceae as they are in plants in general. Preliminary characterization of the identities of the phytoecdysteroids present in the most active extracts has been performed by hplc separations on normal- and reversed-phase systems in conjunction with ecdysteroid-specific radioimmunoassay and bioassay. Each of the phytoecdysteroid-accumulating species examined (Browallia speciosa, Nierembergia hippomanica var violacea, N. solanacea and Solanum nigrum) contain a cocktail of ecdysteroids, of which 20-hydroxyecdysone and polypodine B (5beta,20-dihydroxyecdysone) are major components.

Influenza activity in England and Wales: October 1998 to June 1999

Influenza activity in England and Wales in the winter of 1998/1999 reached the highest weekly levels seen since the epidemic of 1989/1990. Activity peaked at Christmas and the New Year, adding to the winter pressures on general practitioner and hospital services. Adults aged 65 years and over consulted with general practitioners at the highest rates. Outbreaks of influenza or flu-like illness occurred in several schools and nursing homes and, in June 1999, on a British cruise ship in the Mediterranean. Deaths from all causes reached a higher peak in week 1 of 1999 than occurred in the peak week of the influenza epidemic of 1989/90.