Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Design and Implementation of a Pediatric ICU Acuity Scoring Tool as Clinical Decision Support

BACKGROUND AND OBJECTIVE

Pediatric in-hospital cardiac arrest most commonly occurs in the pediatric intensive care unit (PICU) and is frequently preceded by early warning signs of clinical deterioration. In this study, we describe the implementation and evaluation of criteria to identify high-risk patients from a paper-based checklist into a clinical decision support (CDS) tool in the electronic health record (EHR).

MATERIALS AND METHODS

The validated paper-based tool was first adapted by PICU clinicians and clinical informaticians and then integrated into clinical workflow following best practices for CDS design. A vendor-based rule engine was utilized. Littenberg's assessment framework helped guide the overall evaluation. Preliminary testing took place in EHR development environments with more rigorous evaluation, testing, and feedback completed in the live production environment. To verify data quality of the CDS rule engine, a retrospective Structured Query Language (SQL) data query was also created. As a process metric, preparedness was measured in pre- and postimplementation surveys.

RESULTS

The system was deployed, evaluating approximately 340 unique patients monthly across 4 clinical teams. The verification against retrospective SQL of 15-minute intervals over a 30-day period revealed no missing triggered intervals and demonstrated 99.3% concordance of positive triggers. Preparedness showed improvements across multiple domains to our a priori goal of 90%.

CONCLUSION

We describe the successful adaptation and implementation of a real-time CDS tool to identify PICU patients at risk of deterioration. Prospective multicenter evaluation of the tool's effectiveness on clinical outcomes is necessary before broader implementation can be recommended.

Pulmonary Vasodilator Therapy in Shock-associated Cardiac Arrest

RATIONALE

Many in-hospital cardiac arrests are precipitated by hypotension, often associated with systemic inflammation. These patients are less likely to be successfully resuscitated, and novel approaches to their treatment are needed.

OBJECTIVES

To determine if the addition of inhaled nitric oxide (iNO) to hemodynamic-directed cardiopulmonary resuscitation (HD-CPR) would improve short-term survival from cardiac arrest associated with shock and systemic inflammation.

METHODS

In 3-month-old swine (n = 21), LPS was intravenously infused, inducing systemic hypotension. Ventricular fibrillation was induced, and animals were randomized to blinded treatment with either: 1) HD-CPR with iNO, or 2) HD-CPR without iNO. During HD-CPR, chest compression depth was titrated to peak aortic compression pressure of 100 mm Hg, and vasopressor administration was titrated to coronary perfusion pressure greater than or equal to 20 mm Hg. Defibrillation attempts began after 10 minutes of resuscitation. The primary outcome was 45-minute survival.

MEASUREMENTS AND MAIN RESULTS

The iNO group had higher rates of 45-minute survival (10 of 10 vs. 3 of 11; P = 0.001). During cardiopulmonary resuscitation, the iNO group had lower pulmonary artery relaxation pressure (mean ± SEM, 10.9 ± 2.4 vs. 18.4 ± 2.4 mm Hg; P = 0.03), higher coronary perfusion pressure (21.1 ± 1.5 vs. 16.9 ± 1.0 mm Hg; P = 0.005), and higher aortic relaxation pressure (36.6 ± 1.6 vs. 30.4 ± 1.1 mm Hg; P < 0.001) despite shallower chest compressions (5.88 ± 0.25 vs. 6.46 ± 0.40 cm; P = 0.02) and fewer vasopressor doses in the first 10 minutes (median, 4 [interquartile range, 3-4] vs. 5 [interquartile range, 5-6], P = 0.03).

CONCLUSIONS

The addition of iNO to HD-CPR in LPS-induced shock-associated cardiac arrest improved short-term survival and intraarrest hemodynamics.

Health Status following Major Trauma in the West of Scotland: Pilot Descriptive Study

Background

Data on the long-term outcome of major trauma survivors in the United Kingdom (UK) is lacking. This pilot study aimed to investigate the health status of survivors of major trauma without significant head injury in the West of Scotland, and to compare the Short-Form 12 (SF12) questionnaire administered by telephone (TSF12) to the longer Short-Form 36 (SF36) questionnaire.

Methods

This was a descriptive, comparative, pilot clinical study. Eligible patients had an injury severity score (ISS) >15, sustained their injuries >2 years ago, abbreviated injury score (AIS) <2 for head trauma and were treated in two Glasgow hospitals. The Short-Form 36 (SF36) health status questionnaire was completed at home, and the Short-Form 12 (SF12) questionnaire was administered by telephone (TSF12).

Results

From 141 eligible patients (85% male, median age 35 years, median ISS 19 and median Ps 0.981), 13 patients completed the study. Despite small numbers, mean SF36 scores were significantly lower in four dimensions compared to UK means. SF36 summary scores were non-significantly below US and UK means. The TSF12 physical summary score was significantly below US and UK means. Correlations between the SF36 and TSF12, and SF12 intra-class correlations were high. One-way ANOVA showed significantly lower mental summary scores for patients with spinal injuries.

Conclusions

This small study suggests that non-head injured survivors of major trauma have lower health status than the UK average. The TSF12 appears to be a practical alternative to the conventional SF36 and warrants larger scale evaluation.

Explaining trends in alcohol-related harms in Scotland 1991-2011 (II): policy, social norms, the alcohol market, clinical changes and a synthesis

OBJECTIVE

To provide a basis for evaluating post-2007 alcohol policy in Scotland, this paper tests the extent to which pre-2007 policy, the alcohol market, culture or clinical changes might explain differences in the magnitude and trends in alcohol-related mortality outcomes in Scotland compared to England & Wales (E&W).

STUDY DESIGN

Rapid literature reviews, descriptive analysis of routine data and narrative synthesis.

METHODS

We assessed the impact of pre-2007 Scottish policy and policy in the comparison areas in relation to the literature on effective alcohol policy. Rapid literature reviews were conducted to assess cultural changes and the potential role of substitution effects between alcohol and illicit drugs. The availability of alcohol was assessed by examining the trends in the number of alcohol outlets over time. The impact of clinical changes was assessed in consultation with key informants. The impact of all the identified factors were then summarised and synthesised narratively.

RESULTS

The companion paper showed that part of the rise and fall in alcohol-related mortality in Scotland, and part of the differing trend to E&W, were predicted by a model linking income trends and alcohol-related mortality. Lagged effects from historical deindustrialisation and socio-economic changes exposures also remain plausible from the available data. This paper shows that policy differences or changes prior to 2007 are unlikely to have been important in explaining the trends. There is some evidence that aspects of alcohol culture in Scotland may be different (more concentrated and home drinking) but it seems unlikely that this has been an important driver of the trends or the differences with E&W other than through interaction with changing incomes and lagged socio-economic effects. Substitution effects with illicit drugs and clinical changes are unlikely to have substantially changed alcohol-related harms: however, the increase in alcohol availability across the UK is likely to partly explain the rise in alcohol-related mortality during the 1990s.

CONCLUSIONS

Future policy should ensure that alcohol affordability and availability, as well as socio-economic inequality, are reduced, in order to maintain downward trends in alcohol-related mortality in Scotland.

Explaining trends in alcohol-related harms in Scotland, 1991-2011 (I): the role of incomes, effects of socio-economic and political adversity and demographic change

OBJECTIVE

This paper tests the extent to which differing trends in income, demographic change and the consequences of an earlier period of social, economic and political change might explain differences in the magnitude and trends in alcohol-related mortality between 1991 and 2011 in Scotland compared to England & Wales (E&W).

STUDY DESIGN

Comparative time trend analyses and arithmetic modelling.

METHODS

Three approaches were utilised to compare Scotland with E&W: 1. We modelled the impact of changes in income on alcohol-related deaths between 1991-2001 and 2001-2011 by applying plausible assumptions of the effect size through an arithmetic model. 2. We used contour plots, graphical exploration of age-period-cohort interactions and calculation of Intrinsic Estimator coefficients to investigate the effect of earlier exposure to social, economic and political adversity on alcohol-related mortality. 3. We recalculated the trends in alcohol-related deaths using the white population only to make a crude approximation of the maximal impact of changes in ethnic diversity.

RESULTS

Real incomes increased during the 1990s but declined from around 2004 in the poorest 30% of the population of Great Britain. The decline in incomes for the poorest decile, the proportion of the population in the most deprived decile, and the inequality in alcohol-related deaths, were all greater in Scotland than in E&W. The model predicted less of the observed rise in Scotland (18% of the rise in men and 29% of the rise in women) than that in E&W (where 60% and 68% of the rise in men and women respectively was explained). One-third of the decline observed in alcohol-related mortality in Scottish men between 2001 and 2011 was predicted by the model, and the model was broadly consistent with the observed trends in E&W and amongst women in Scotland. An age-period interaction in alcohol-related mortality was evident for men and women during the 1990s and 2000s who were aged 40-70 years and who experienced rapidly increasing alcohol-related mortality rates. Ethnicity is unlikely to be important in explaining the trends or differences between Scotland and E&W.

CONCLUSIONS

The decline in alcohol-related mortality in Scotland since the early 2000s and the differing trend to E&W were partly described by a model predicting the impact of declining incomes. Lagged effects from historical social, economic and political change remain plausible from the available data.

Diverse Morbidity and Mortality Among Infants Treated with Venoarterial Extracorporeal Membrane Oxygenation

Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is utilized for cardiopulmonary failure. We aimed to qualify and quantify the predictors of morbidity and mortality in infants requiring VA-ECMO.

Methods: Data was collected from 170 centers participating in the extracorporeal life support organization (ELSO) registry. Relationships between in-hospital mortality and risk factors were assessed using logistic regression. Survival was defined as being discharged from the hospital.

Results: Six hundred and sixty-two eligible records were reviewed. Mortality occurred in 303 (46%) infants. Congenital diaphragmatic hernia patients (OR=3.83, 95% CI 1.96-7.49, p<0.001), cardiac failure with associated shock (OR= 2.90, 95% CI 1.46-5.77, p=0.002), and pulmonary failure including respiratory distress syndrome (OR=4.06, 95% CI 1.72-9.58, p=0.001) had the highest odds of mortality in this cohort. Birth weight (BW) < 3 kg (OR=1.83, 95% CI 1.21-2.78, p=0.004), E-CPR (OR=3.35, 95% CI 1.57-7.15, p=0.002), hemofiltration (OR=2.04, 95% CI 1.32-3.16, p=0.001), and dialysis (OR=6.13, 95% CI 1.70-22.1, p<0.001) were all independent predictors of mortality.

Conclusion: Infants requiring VA-ECMO experience diverse sequelae and their mortality are high.

Developing quality indicators for family support services in community team-based mental health care

Quality indicators for programs integrating parent-delivered family support services for children's mental health have not been systematically developed. Increasing emphasis on accountability under the Affordable Care Act highlights the importance of quality-benchmarking efforts. Using a modified Delphi approach, quality indicators were developed for both program level and family support specialist level practices. These indicators were pilot tested with 21 community-based mental health programs. Psychometric properties of these indicators are reported; variations in program and family support specialist performance suggest the utility of these indicators as tools to guide policies and practices in organizations that integrate parent-delivered family support service components.

Meeting report for mobile DNA 2010

An international conference on mobile DNA was held 24-28 April 2010 in Montreal, Canada. Sponsored by the American Society for Microbiology, the conference's goal was to bring together researchers from around the world who study transposition in diverse organisms using multiple experimental approaches. The meeting drew over 190 attendees and most contributed through poster presentations, invited talks and short talks selected from poster abstracts. The talks were organized into eight scientific sessions, which ranged in topic from the evolutionary dynamics of mobile genetic elements to transposition reaction mechanisms. Here we present highlights from the platform sessions with a focus on talks presented by the invited speakers.

Respiratory distress associated with inadequate mechanical ventilator flow response in a neonate with congenital diaphragmatic hernia

The incidence of congenital diaphragmatic hernia has been reported as 0.17-0.66 per 1,000 births. Despite advances in neonatal intensive care, congenital diaphragmatic hernia is associated with high mortality and morbidity. We report a neonate who was born with a left congenital diaphragmatic hernia and underwent surgical repair. The lack of ventilator flow response and flow cycling was identified via interpretation of the ventilator graphic and clinical assessment. Presumably, the ventilator failed to respond to the patient's peak inspiratory flow demand, despite the clinician's setting the highest peak flow available. A time-cycled pressure-limited mode with adjustable peak flow rate was the only option that met the infant's flow requirement, and alleviated the respiratory distress. This clinical finding follows bench research that raises the concern that so called "cradle-to-grave" ventilators may not optimally support all neonates.

Extracorporeal membrane oxygenation for neonatal respiratory failure

Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary bypass adapted for long-term use. Blood is drained from the patient, pumped through an artificial lung or membrane where gas exchange is augmented, and then re-infused back to the patient. ECMO provides support for the neonate with severe respiratory failure so that potentially deleterious ventilator settings can be minimized and the disease process given time to resolve. Survival rates and long-term neurodevelopmental outcomes in newborns supported with ECMO for hypoxemic respiratory failure remain favorable, although the use of ECMO has decreased in the most recent decade because of the availability of alternative treatment options.

Extracorporeal membrane oxygenation as a bridge to definitive tracheal reconstruction in neonates

PURPOSE

Infants born with severe tracheal anomalies may not survive beyond the first few hours of life without aggressive cardiopulmonary support and/or emergent airway surgery. The purpose of this study was to review our experience with critically ill neonates supported on extracorporeal membrane oxygenation (ECMO) before tracheal reconstruction.

METHODS

A retrospective review of a single institution ECMO registry was conducted. Outcomes of neonates requiring tracheal repair were examined.

RESULTS

Three children with tracheal anomalies (complete tracheal rings [n = 2]; bronchogenic cyst [n = 1]) underwent definitive airway reconstruction. All were placed on ECMO (venovenous [n = 2]; venoarterial [n = 1]) within 24 hours after birth. Tracheoplasties (tracheal resection with end-to-end anastomosis [n = 1]; slide tracheoplasty [n = 1]; carinal resection and reconstruction [n = 1]) were performed at 3.7 +/- 2.2 days of life. There were no hemorrhagic or thrombotic complications for an ECMO time of 117.3 +/- 60.1 hours. The postoperative durations until extubation and hospital discharge were 12.0 +/- 3.2 and 34.3 +/- 11.6 days, respectively. All children remain alive and well without cardiopulmonary and neurologic sequelae at a mean follow-up of 4.5 years.

CONCLUSIONS

Excellent clinical outcomes can be achieved in neonates born with severe tracheal anomalies using ECMO as a bridge to definitive tracheal reconstruction.

Pediatric staff perspectives on organ donation after cardiac death in children

OBJECTIVES

The aims of this project were to describe whether pediatric clinical staff members believe that a donation after cardiac death (DCD) program could be consistent with the mission and core values of a children's hospital and to identify what staff consider essential to the acceptability of such a program.

DESIGN

Qualitative study.

SETTING

Children's hospital.

SUBJECTS

Pediatric clinical staff.

INTERVENTIONS

Data were gathered from pediatric clinical staff during eight focus groups conducted in a children's hospital in March and April 2005.

MEASUREMENTS AND MAIN RESULTS

Eighty-eight staff members participated. Six major themes emerged from qualitative analysis of the data: a) identifying children who could be candidates for DCD; b) considering the best interests of the dying child; c) approaching parents about DCD; d) preparing parents for their child's DCD; e) doing DCD well; and f) maintaining program integrity. Themes were used to construct a conceptual framework describing a model pediatric DCD program. Pediatric staff voiced numerous concerns. However, they identified "making it happen for families" who voice a desire to participate in organ donation as the primary reason for program adoption.

CONCLUSIONS

This study provides a framework for understanding pediatric staff perspectives on DCD programs in children. Results suggest several possible elements that may be helpful in framing interdisciplinary dialogue and informing institutional practices in the design of a pediatric DCD program.

Haploinsufficiency-based large-scale forward genetic analysis of filamentous growth in the diploid human fungal pathogen C.albicans

Candida albicans is the most prevalent human fungal pathogen. Here, we take advantage of haploinsufficiency and transposon mutagenesis to perform large-scale loss-of-function genetic screen in this organism. We identified mutations in 146 genes that affect the switch between its single-cell (yeast) form and filamentous forms of growth; this switch appears central to the virulence of C.albicans. The encoded proteins include those involved in nutrient sensing, signal transduction, transcriptional control, cytoskeletal organization and cell wall construction. Approximately one-third of the genes identified in the screen lack homologs in Saccharomyces cerevisiae and other model organisms and thus constitute candidate antifungal drug targets. These results illustrate the value of performing forward genetic studies in bona fide pathogens.

Can primary care be both patient-centred and community-led?

Examines the relationships between the macro-, meso-, and micro-levels in the NHS at the end of the fundholding period and considers their contemporary implications for primary care groups (PCGs) and local health care co-operatives (LHCCs). Fundholding achieved some success in challenging the way in which services were provided at the micro-level (the practice), but had a less marked effect in terms of changing service provision at the health authority (meso-) level or in developing collaborative working with trusts and health authorities in strategic decision making. The health authorities prioritized alternative models of devolved commissioning. Trusts regarded fundholders as a distraction who exerted influence and commanded trust management time disproportionate to their "market share". PCGs and LHCCs represent a shift back to the meso-level in service planning and purchasing. As such there is a risk that the micro-level benefits of fundholding and other forms of devolved commissioning will be lost, while uncertainties remain regarding the capacity of PCGs and LHCCs to incorporate GPs into a collaborative approach to strategic decision making.

Distraction lengthening of the radius for radial longitudinal instability after distal radio-ulnar subluxation and excision of the radial head: a case report

The results of late surgery for symptomatic proximal migration of the radius after resection of the radial head for trauma are usually disappointing. Ulnar variance increases when the interosseous membrane is disrupted. Its integrity should be assessed to predict the results of further surgery. We describe a 29-year-old patient in whom distraction lengthening of the radius through an Ilizarov frame allowed him to regain pain-free function of the wrist and elbow after a complex Essex-Lopresti fracture dislocation and late symptoms of ulnar carpal impingement.

Relationship between dynamical and equilibrium characteristics of glass-forming polymeric liquids

A connection between measurable equilibrium thermodynamic quantities and a nonequilibrium property of supercooled polymeric liquids, namely, the fragility index, is proposed within the framework of a synthesis of generalized configurational entropy models. The theoretical predictions are compared with experimental data on five glass-forming polymers.

Randomised trial of personalised computer based information for patients with schizophrenia

OBJECTIVES

To compare use, effect, and cost of personalised computer education with community psychiatric nurse education for patients with schizophrenia.

DESIGN

Randomised trial of three interventions. Modelling of costs of alternatives.

PARTICIPANTS

112 patients with schizophrenia in contact with community services; 67 completed the intervention.

INTERVENTIONS

Three interventions of five educational sessions: (a) computer intervention combining information from patient's medical record with general information about schizophrenia; (b) sessions with a community psychiatric nurse; (c) "combination" (first and last sessions with nurse and remainder with computer).

MAIN OUTCOME MEASURES

Patients' attendance, opinions, change in knowledge, and psychological state; costs of interventions and patients' use of NHS community services; modelling of costs for these three, and alternative, interventions.

RESULTS

Rates of completion of intervention did not differ significantly (71% for combination intervention, 61% for computer only, 46% for nurse only). Computer sessions were shorter than sessions with nurse (14 minutes v 60 minutes). More patients given nurse based education thought the information relevant. Of 20 patients in combination group, 13 preferred the sessions with the nurse and seven preferred the computer. There were no significant differences between groups in psychological outcomes. Because of the need to transport patients to the computer for their sessions, there was no difference between interventions in costs, but computer sessions combined with other patient contacts would be substantially cheaper.

CONCLUSIONS

The computer based patient education offered no advantage over sessions with a community psychiatric nurse. Investigation of computer use combined with other health service contacts would be worth while.

Measuring the costs and benefits of heart disease monitoring

OBJECTIVE

To evaluate the costs and benefits of alternative systems of coronary heart disease monitoring in Scotland.

DESIGN

An option appraisal was conducted to evaluate the costs and benefits of implementing a coronary heart disease monitoring system. This involved a review of existing Scottish datasets and relevant reports, specification of options, definition and weighting of benefit criteria by key stakeholders, assessment of options by experts, and costing of options. The options were assessed by 33 stakeholders (grouped as cardiologists, patient representatives, general practitioners, public health physicians, and policy makers), plus 13 topic experts.

SETTING

Scotland (population 5.1 million).

RESULTS

Between group mean benefit weights were: mortality rates and case fatality (10.6), quality of life (9.8), patient function (8.8), hospital activity (7.8), primary care activity (9.25), prescribing (5.72), socioeconomic impact (4.0), risk factors (7.4), prevalence (5.0), incidence (6.0), case registration (6.82), international comparability (4.2), breadth of coverage (8.8), and frequency (5.8). Differences between group weights were significant for prevalence (p = 0.048) and international comparability (p = 0.032). Four monitoring options were identified: a community epidemiology model, based on MONICA (monitoring trends and determinants in cardiovascular disease) study methodology applied to a series of eight representative communities, had the highest benefits, at an average annual discounted cost of approximately pound 360,000; models based on the Australian cardiovascular disease monitoring scheme and on enhanced routine data offered fewer benefits at discounted average annual costs ranging from pound 165,000 to pound 195,000; finally, a coronary heart disease registry modelled on the Scottish Cancer Registry scheme would have had fewer benefits and substantially higher costs than the other options.

CONCLUSIONS

The most beneficial coronary heart disease monitoring system is the community epidemiology model, based on MONICA methodology. Option appraisal potentially offers an explicit and transparent methodology for evidence based policy development.

Randomised trial of personalised computer based information for cancer patients

OBJECTIVE

To compare the use and effect of a computer based information system for cancer patients that is personalised using each patient's medical record with a system providing only general information and with information provided in booklets.

DESIGN

Randomised trial with three groups. Data collected at start of radiotherapy, one week later (when information provided), three weeks later, and three months later.

PARTICIPANTS

525 patients started radical radiotherapy; 438 completed follow up.

INTERVENTIONS

Two groups were offered information via computer (personalised or general information, or both) with open access to computer thereafter; the third group was offered a selection of information booklets.

OUTCOMES

Patients' views and preferences, use of computer and information, and psychological status; doctors' perceptions; cost of interventions.

RESULTS

More patients offered the personalised information said that they had learnt something new, thought the information was relevant, used the computer again, and showed their computer printouts to others. There were no major differences in doctors' perceptions of patients. More of the general computer group were anxious at three months. With an electronic patient record system, in the long run the personalised information system would cost no more than the general system. Full access to booklets cost twice as much as the general system.

CONCLUSIONS

Patients preferred computer systems that provided information from their medical records to systems that just provided general information. This has implications for the design and implementation of electronic patient record systems and reliance on general sources of patient information.

Cloning, expression, and physical mapping of the 3beta-hydroxysteroid dehydrogenase gene cluster (HSD3BP1-HSD3BP5) in human

Seven members of the human 3beta-hydroxysteroid dehydrogenase (3beta-HSD) gene family (HGMW-approved symbols HSD3BP1-HSD3BP5) have been cloned and physically mapped. HSD3B1 and 2 express 3beta-HSD enzymes; HSD3Bpsi1-5 are unprocessed pseudogenes that are closely related to HSD3B1 and 2 but contain no corresponding open reading frames. mRNA is expressed from psi4 and psi5 in several tissues, but with altered splice sites that disrupt reading frames. A 0.5-Mb contig of 3 yeast artificial chromosome and 32 bacterial artificial chromosome genomic clones contained no additional members of the gene family. The seven genes and pseudogenes mapped within 230 kb in the order HSD3Bpsi5-psi4-psi3-HSD3B1-psi1-psi2 -HSD3B2. HSD3B1 and 2 are in direct repeat, 100 kb apart. Six HSD3B2 mutations involve substitutions that are present in several of the pseudogenes. In four cases, mutations arose in CpG sites that are conserved within the gene cluster. The tendency for CpG sites to mutate by transition provides an adequate explanation for these HSD3B2 mutations, which are unlikely to be due to recombination or conversion within the gene family.

Measuring progress towards a primary care-led NHS

BACKGROUND

The push towards a 'primary care-led' National Health Service (NHS) has far-reaching implications for the future structure of the NHS. The policy involves both a growing emphasis on the role of primary care practitioners in the commissioning of health services, and a change from hospital to primary and community settings for a range of services and procedures. Although the terminology has changed, this emphasis remains in the recent Scottish Health Service White Paper and its English counterpart.

AIM

To consider three questions in relation to this policy goal. First, does the evidence base support the changes? Secondly, what is the scale of the changes that have occurred? Thirdly, what are the barriers to the development of a primary care-led NHS?

METHOD

Programme budgets were compiled to assess changes over time in the balance of NHS resource allocation with respect to primary and secondary care. Total NHS revenue expenditure for the 15 Scottish health boards was grouped into four blocks or 'programmes': primary care, secondary care, community services, and a residual. The study period was 1991/2 to 1995/6. Expenditure data were supplied by the Scottish Office.

RESULTS

Ambiguity of definitions and the absence of good data cause methodological difficulties in evaluating the scale and the appropriateness of the shift. The data that are available suggest that, at the aggregate level, there have been changes over time in the balance of resource allocation between care settings: relative investment into primary care has increased. It would appear that this investment is relatively small and from growth money rather than a 'shift' from secondary care. In addition, the impact of GP-led commissioning is variable but limited.

CONCLUSION

General practitioners' (GPs') attitudes to the policy suggest that progress towards a primary care-led NHS will continue to be patchy. The limited shift to date, alongside evidence of ambivalent attitudes to the shift on the part of GPs, suggest that this is a policy objective that may not be achieved.

Computer simulation to estimate the effectiveness of carotid endarterectomy

OBJECTIVES

To investigate the benefit of carotid endarterectomy relative to medical treatment, by comparing the outcome for different groups of patients following transient ischaemic attacks.

METHODS

A Markov model was used to describe the survival and quality of life of patients treated for a transient ischaemic attack. The benefit is measured in terms of quality adjusted life months (QALMs). The outcome was estimated using a computer simulation with parameters based on published studies on the probability of events following treatment. The benefit of carotid endarterectomy was explored using a baseline set of parameters and a sensitivity analysis.

RESULTS

The baseline scenario of a 65-year-old male patient with the model factors set at an intermediate level showed a benefit for surgery of 3 QALMs compared with medical treatment alone. The sensitivity analysis showed that the most favourable combination of factors had a benefit of 13.4 QALMs and the least favourable a loss of 2 QALMs. Of all 128 factor combinations, 79.9% showed a benefit for surgery, 5.5% showed equal benefit, and 15.6% showed a benefit for medical treatment.

CONCLUSIONS

Computer simulations have the potential for deriving estimates of benefit for different patient groups from the results of clinical trials. Combined with reliable information on costs, the technique could also demonstrate variations in cost-effectiveness for these groups. For patients following a transient ischaemic attack, the results from this simulation and limited cost information suggest that carotid endarterectomy is unlikely to be a cost-effective intervention in the UK for many patient groups despite a reduction in the risk of stroke.

Less fog on the Tyne? Programme budgeting in Newcastle and North Tyneside

Programme Budgeting (PB) has been widely promoted as a model for the better conduct of the work of Health Authorities in the National Health Service in the United Kingdom. This paper reports on a project which looked at the development of PB in Newcastle and North Tyneside Health Authority (NNTHA), concentrating on the construction of a computerised tool for the compilation and analysis of programme budgets. The main activities carried out were a survey of user requirements for PB, a survey of data availability, the collection of data to construct programme budgets, and development of a relational database for storing and manipulating PB information. The main source of data was the Contract Minimum Data Set, which was supplemented by data from a number of other sources to give comprehensive information on spending in NNTHA. Costed activity data were produced, which could be aggregated in a large number of ways, such as by care setting (inpatient, outpatient, community, general practice, etc.), disease group (ICD9 chapter headings), case mix (Healthcare Resource Groups) and socio-demographic variables (age/sex, locality of GPs practice).

Choice and accountability in health promotion: the role of health economics

Choices need to be made between competing uses of health care resources. There is debate about how these choices should be made, who should make them and the criteria upon which they should be made. Evaluation of health care is an important part of this debate. It has been suggested that the contribution of health economics to the evaluation of health promotion is limited, both because the methods and principles underlying economic evaluation are unsuited to health promotion, and because the political and cultural processes governing the health care system are more appropriate mechanisms for allocating health care resources than systematic economic analysis of the costs and benefits of different health care choices. This view misrepresents and misunderstands the contribution of health economics to the evaluation of health promotion. It overstates the undoubted methodological difficulties of evaluating health promotion. It also argues, mistakenly, that economists see economic evaluation as a substitute for the political and cultural processes governing health care, rather than an input to them. This paper argues for an economics input on grounds of efficiency, accountability and ethics, and challenges the critics of the economic approach to judge alternative mechanisms for allocating resources by the same criteria.

Clearing the fog on the Tyne: programme budgeting in Newcastle and North Tyneside Health Authority

When the internal market was introduced, the National Health Service Management Executive envisaged purchasing as a process by which contracts would be developed from information concerning current services, modified in the light of strategic purchasing objectives, epidemiological needs assessment and indicators of comparative performance and efficiency. Our concern in this paper is with the promotion of efficiency. We distinguish between three levels and, in particular, discuss how the programme budgeting and marginal analysis framework can be used in the promotion of efficiency at 'top-level' decision making. PB/MA can be used to give a focus to needs assessment and forge explicit links between individual contracts within a well defined health strategy. The objectives of the current research and development ongoing within Newcastle and North Tyneside Health Authority are outlined. The intention is to achieve programme budgeting which is more responsive to decision makers' needs and is consistent with the contracting cycle. However, a number of constraints are expected to impede development. They include transferability of national and international information; absence of local information on epidemiology, effectiveness and cost-effectiveness; limitations on the accuracy and precision of programme budgets; and whether purchasers make strategic decisions based on macro budgets. The contribution of each of these constraints is explored.

The limits of the possible: models of power supply and demand in cycling

This paper outlines a general strategy for mathematical modeling of cycling performance. This strategy involves formulating one expression describing the power available for external work from physiological sources. The variables used in this expression include maximal aerobic power (VO2max), fractional utilisation of VO2max, mechanical efficiency, maximal accumulated oxygen deficit, and the time constants relating to the expression of aerobic and anaerobic capacities. A second expression describing the power demand of cycling is then constructed. The variables used in this expression include the mass, projected frontal area and drag characteristics of the system, the coefficient of rolling resistance, environmental variables such as temperature, barometric pressure, relative humidity, wind speed and direction and the slope of the course. The two expressions are equated and solved using an iterative procedure. Two series of trials were used to assess the predictive accuracy of the model, one using track endurance performances and the other a 26 km road time-trial. The correlations between actual and predicted times have been excellent (0.92-0.95, p < or = 0.0001), with small mean differences (0-1.83% of mean performance time) and mean absolute differences (1.07-3.24%). The model allows us to make predictions about the effect of equipment changes and environmental factors, to compare performances under very different conditions, and to predict the limits of the possible in cycling performance. A range of options designed to improve cycling performance is described.

Processing of eukaryotic ribosomal RNA

In summary, it can be argued that the understanding of eukaryotic rRNA processing is no less important than the understanding of mRNA maturation, since the capacity of a cell to carry out protein synthesis is controlled, in part, by the abundance of ribosomes. Processing of pre-rRNA is highly regulated, involving many cellular components acting either alone or as part of a complex. Some of these components are directly involved in the modification and cleavage of the precursor rRNA, while others direct the packaging of the rRNA into ribosome subunits. As is the case for pre-mRNA processing, snoRNPs are clearly involved in eukaryotic rRNA processing, and have been proposed to assemble with other proteins into at least one complex called a "processosome" (17), which carries out the ordered processing of the pre-rRNA and its assembly into ribosomes. The formation of a processing complex clearly makes possible the regulation required to coordinate the abundance of ribosomes with the physiological and developmental changes of a cell. It may be that eukaryotic rRNA processing is even more complex than pre-mRNA maturation, since pre-rRNA undergoes extensive nucleotide modification and is assembled into a complex structure called the ribosome. Undoubtedly, features of the eukaryotic rRNA-processing pathway have been conserved evolutionarily, and the genetic approach available in yeast research (6) should provide considerable knowledge that will be useful for other investigators working with higher eukaryotic systems. Interestingly, it was originally hoped that the extensive work and understanding of bacterial ribosome formation would provide a useful paradigm for the process in eukaryotes. However, although general features of ribosome structure and function are highly conserved between bacterial and eukaryotic systems, the basic strategy in ribosome biogenesis seems to be, for the most part, distinctly different. Thus, the detailed molecular mechanisms for rRNA processing in each kingdom will have to be independently deciphered in order to elucidate the features and regulation of this important process for cell survival.

Lanterns in the jungle: is the NHS driven by the wrong kind of efficiency?

The performance of the National Health Service is assessed in part by an Efficiency Index (EI) which is applied to the service as a whole as well as to individual health authorities. The EI relates increases in the amount of patient care activity to increases in total expenditure. The index can give a misleading impression of performance, creates perverse incentives and is at odds with the overall strategy of the health service which is to place greater emphasis on the promotion of health and to provide more care in primary and community-based settings. The philosophy, validity and appropriateness of the EI are discussed.

Preferential transposition of Drosophila P elements to nearby chromosomal sites

Two different schemes were used to demonstrate that Drosophila P elements preferentially transpose into genomic regions close to their starting sites. A starting element with weak rosy+ marker gene expression was mobilized from its location in the subtelomeric region of the 1,300-kb Dp1187 minichromosome. Among progeny lines with altered rosy+ expression, a much higher than expected frequency contained new insertions on Dp1187. Terminal deficiencies were also recovered frequently. In a second screen, a rosy(+)-marked element causing a lethal mutation of the cactus gene was mobilized in male and female germlines, and viable revertant chromosomes were recovered that still contained a rosy+ gene due to an intrachromosomal transposition. New transpositions recovered using both methods were mapped between 0 and 128 kb from the starting site. Our results suggested that some mechanism elevates the frequency 43-67-fold with which a P element inserts near its starting site. Local transposition is likely to be useful for enhancing the rate of insertional mutation within predetermined regions of the genome.

Umbilical cord knots and encirclements

Although cord knots and/or encirclements account for 1 in 10 stillbirths of infants weighing 2,500 g or more, no problem due to this cause was encountered in a prospective study of 1,115 vaginal deliveries. In this study there were 6 cases of cord knot (0.5%) and 158 of cord encirclement (14.2%). The range of cord length was 27-122 cm, the 10th, 50th and 90th percentiles being 40, 52 and 69 cm respectively. In this study there was no clinical warning (fetal distress) of cord encirclement or knot during pregnancy, labour or delivery.

Primary processing of mammalian rRNA involves two adjacent cleavages and is not species specific

The primary transcript of the mouse rRNA gene is rapidly processed at nucleotide approximately +650 both in vivo and in vitro. Using run-off transcription in a mouse cell extract as well as S1 nuclease and primer extension analysis of cellular RNA, we demonstrated that this primary processing actually results in the formation of two species of downstream RNA which differ in length by approximately 6 nucleotides, indicating the existence of two closely positioned alternative processing sites. The 200-base-pair region just 3' to the mouse processing site has a striking 80% sequence homology with a region of the human rRNA external transcribed spacer, and S1 nuclease analysis of human cellular RNA has demonstrated that an analogous rRNA processing occurs at the 5' border of the homologous human region. Unlike rDNA transcriptional initiation, however, the primary rRNA processing is not highly species specific, for the transcript of a chimeric gene containing the human processing region adjacent to a mouse rDNA promoter was synthesized and correctly processed in a mouse cell extract. This result confirms that mouse and human rRNA undergo a common primary processing event which is evidently directed by sequences within the 200-base-pair conserved sequence region.

Nucleotide sequence determining the first cleavage site in the processing of mouse precursor rRNA

The first step in the processing of 47S precursor rRNA in mouse cells is reproduced in vitro in an S-100 transcription reaction and consists of an endonucleolytic cleavage at residue +650 of the primary transcript followed by rapid degradation of the fragment upstream from residue +650. An analogous processing occurs in human rRNA. The mouse and human rRNA sequences are approximately equal to 80% conserved for 200 nucleotides on the 3' side of these processing sites, suggesting that this conserved region may be important in specifying the processing. To test this hypothesis, we constructed a systematic series of deletion mutants approaching the mouse rDNA processing region from both the 5' and 3' directions and analyzed the processing of their transcripts in vitro. The 5' boundary of the region required for processing is quite sharp and corresponds to the rRNA cleavage site at the 5' end of the conserved sequence region. The 3' boundary is more complex: The 3' deletions extending to between 250 and 130 nucleotides beyond the processing site cause about a 50% decrease in the amount of the processed RNA. A 3' deletion that extends to 109 nucleotides beyond the processing site greatly reduces the processing efficiency. Deletions to or beyond 91 nucleotides on the 3' side of the processing site virtually eliminate processing. Under altered ionic conditions, transcripts of 3' deletions extending to only 41 nucleotides beyond the processing site can still direct a low level of accurate processing. These results demonstrate that the mouse/human conserved sequence just on the 3' side of the primary rRNA processing site consists of several domains that direct and/or augment both the initial endonucleolytic cleavage and the closely coupled selective degradation of the upstream fragment that together constitute the primary rRNA processing event.

Treatment of Chinese hamster ovary cells with the transcriptional inhibitor actinomycin D inhibits binding of messenger RNA to ribosomes

Inhibitors of RNA synthesis such as actinomycin D, MPB, and cordycepin progressively inhibit the initiation of protein synthesis in intact, nucleated mammalian cells. This inhibition is not dependent on the levels of mRNA, ribosomes, or tRNA. Lysates prepared from CHO cells treated with actinomycin D do not incorporate labeled globin mRNA or ovalbumin mRNA into 80S initiation complexes at the rates of untreated control extract. The ability of the extracts to produce and accumulate 48S preinitiation complexes was assessed using the 60S subunit joining inhibitors edeine and 5'-guanylyl imidodiphosphate. Control extracts were able to accumulate both the 48S preinitiation complexes and the migration-related intermediates in the presence of both inhibitors. However, lysates derived from CHO cells treated with actinomycin D were unable to produce these complexes. This was also true at low temperature, a condition that does not inhibit mRNA binding but prevents migration of the 43S complex along the mRNA. Mixing experiments with extracts from untreated control or AMD-treated CHO cells provided no evidence for a translational inhibitor. Thus, our data are consistent with the hypothesis that treatment of whole cells with actinomycin D inhibits protein synthesis initiation at the level of mRNA binding and not at migration or 60S subunit joining.

Inhibition of protein synthesis in CHO cells by actinomycin D: lesion occurs after 40S initiation complex formation

Inhibitors of RNA synthesis such as actinomycin D, 2-mercapto-1-(beta-4-pyridylethyl)benzimidazole, and cordycepin progressively inhibit the initiation of protein synthesis in intact nucleated mammalian cells independent of their effect on mRNA synthesis. The mechanism of this effect is unknown. The activity of cell-free lysates is not directly affected by these inhibitors, suggesting that their effect is indirect and requires an intact cell. However, lysates prepared from L-cells or CHO cells treated with the inhibitors do exhibit a decrease in initiation activity corresponding in magnitude to the effect seen in intact cells. Mixing experiments with lysates isolated from untreated or treated cells provide no evidence for a translational inhibitor. However, experiments analyzing the incorporation of [35S]methionine and [35S]Met-tRNAf into initiation complexes showed that while the level of labeled 40S initiation complex in lysates from treated cells was the same or higher than in control lysates, the rate or efficiency of formation of the 80S initiation complex was inhibited. These results imply that the transcriptional inhibitors do not affect the level or charging of the initiation tRNAMet, the activity of the eIF-2 initiation factor needed for ternary complex formation, and the availability of active 40S ribosomal subunits. Thus, this site of action is different from that observed in other translational control systems such as the hemin response in reticulocytes and the interferon-induced translation inhibition in virally infected cells. This effect may reflect the cell's coordination of nuclear transcription and cytoplasmic translation.