Accurate power approximations for chi2-tests in case-control association studies of complex disease genes

A popular method for the analysis of case-control association studies is to compare the frequencies of the alleles between cases and controls by means of Pearson's chi2-statistic. Here, an approach for computing the power of this test is presented, which by computer simulation is shown to be more reliable than a previously published power approximation. Since the test based on Pearson's chi2- statistic can be anti-conservative if there is an excess of homozygotes for the susceptibility allele in the general population, it has been proposed to analyze case-control association studies by means of a trend test based on genotypes instead of alleles. We present an accurate power approximation for the trend test. The power approximations are implemented in an available computer program 'GenOdyPower', which in addition has an option to determine the empirical power of these tests by simulations.

Costs of village community, residential campus and dispersed housing provision for people with intellectual disability

BACKGROUND

In recent years, a growing volume of research evidence has been generated about the relative cost-effectiveness of various types of community-based residential supports for people with intellectual disability (ID) in the UK. However, few reliable data are available to inform planners, commissioners or service providers about the quality and costs of providing support within residential or village communities.

METHODS

The evaluation described in the present paper aimed to fill some of the gaps in knowledge by examining the comparative costs of supporting people in village community settings, in National Health Service (NHS) residential campuses and in dispersed, community-based housing schemes. The complete service package received by each study participant was described and costed, and a series of statistical analyses was undertaken to identify factors associated with variations in the cost of support. The analyses reported in the present paper were based on comparisons of 86 people living in village communities, 133 in residential campuses and 281 in dispersed housing schemes.

RESULTS

Wide variations in cost were found, not only between models of accommodation, but between individual organizations, settings and service users. Multivariate analysis revealed that higher costs were associated with supports for people with higher levels of ID and more severe challenging behaviour. The cost of support was affected by the size of the residential setting, with smaller facilities likely to be more expensive. Associations were also found between increased costs, and services for younger users, male users and people who had not moved from a NHS hospital. Generally, more sophisticated service processes within the setting were associated with higher costs; although systematic arrangements for supervision and training of staff had a negative effect on cost.

CONCLUSIONS

The cost findings should be considered alongside evidence on outcomes. A comparison of village communities and dispersed housing schemes suggests that both models of provision appear be associated with particular benefits, although different types of setting are appropriate for different individuals and therefore, the continued development of a range of residential models is important.

Depot antipsychotic preparations in schizophrenia: the state of the economic evidence

Depot treatment of schizophrenia - to date restricted to conventional antipsychotic medications - remains widespread. Whilst there have been numerous studies of clinical effectiveness, and systematic reviews of the accumulated evidence, little appears to be known about the cost-effectiveness of depot treatment. A systematic review was conducted of the international literature in an attempt to find, appraise and summarize the economic evaluative evidence. Very few studies of relevance or quality could be found. Most of the papers purporting to examine the economic consequences of depot treatment were methodologically weak. There were no randomized controlled trials of depot vs. oral antipsychotics, the few mirror-image studies were uncontrolled and a single naturalistic observational study measured costs only narrowly. Two modelling studies - which have a number of limitations because of their partial reliance on expert opinion rather than observational data - suggest that depot treatment may lower costs and improve cost-effectiveness. Overall, however, it is not possible to draw conclusions as to the cost-effectiveness of depot conventional antipsychotic treatment for schizophrenia.

Heavy users of acute psychiatric beds: randomized controlled trial of enhanced community management in an outer London borough

BACKGROUND

Heavy users of psychiatric services, often defined as the population that uses the most beds, consume a large part of the resources used by the whole service, despite being relatively small in number. Any intervention that reduces heavy use is therefore likely to lead to significant savings, and enhancement of standard care using a form of intensive case management akin to assertive community treatment was thought to be a pragmatic strategy for testing in this group.

METHODS

The effectiveness of enhanced community management (ECM) was compared with standard care alone in heavy users, who represented the 10% of patients with the highest number of hospital admissions and occupied bed days over the previous 6.5 years in an outer London borough. One hundred and ninety-three patients were randomly assigned to ECM or standard care and their use of services was determined after 1 and 2 years, with assessments of costs, clinical symptoms, needs, and social function made before entry into the study and after 1 and 2 years.

RESULTS

Despite a 24 fold increase in community contacts in the study group, there were no significant differences between the two groups in any of the main outcome measures. Small savings on in-patient and day-hospital service costs were counterbalanced by the increased costs of outpatient and community care for the subjects assigned to ECM. Clinical outcome data derived from interviews in two-thirds of the subjects were similar in both groups.

CONCLUSIONS

Providing additional intensive community focused care to a group of heavy users of psychiatric in-patient services in an outer London borough does not lead to any important clinical gains or reduced costs of psychiatric care.

Home treatment for mental health problems: a systematic review

BACKGROUND

Concerns have been raised about the scope and generalizability of much community mental health research. In particular, both experimental and control services are poorly characterized.

METHODS

To review the effectiveness of 'home treatment' for mental health problems in terms of hospitalization, we conducted a systematic review, using Cochrane methodology but with a wider remit. Non-randomized studies were included in response to concerns about RCTs' generalizability. All authors were followed up for data on service components. 'Home treatment' was defined broadly for the purposes of the literature search, but included studies were then assessed against service components specifically focused on delivering treatment at home. The study tested components and other features for associations with days in hospital, as well as conducting a conventional meta-analysis of data on days in hospital.

RESULTS

We found 91 studies, 18 comparing home to in-patient treatment. Sixty per cent of authors responded to follow-up. The vast majority of the services studied had a 'home treatment function' and regularly visited patients at home. The heterogeneity of control services made meta-analysis problematical as did the limited availability of data. There was some evidence that 'regular' home visiting and combined responsibility for health and social care were associated with reduced hospitalization. The inclusion of non-randomized studies rarely affected the findings.

CONCLUSIONS

Evidence concerning the effectiveness of home treatment remains inconclusive. A centrally coordinated research strategy is recommended, with attention to study design. Experimental and control service components should be prospectively recorded and reported to enable meaningful analysis.

Structural basis for abrogated binding between staphylococcal enterotoxin A superantigen vaccine and MHC-IIalpha

Staphylococcal enterotoxins (SEs) are superantigenic protein toxins responsible for a number of life-threatening diseases. The X-ray structure of a staphylococcal enterotoxin A (SEA) triple-mutant (L48R, D70R, and Y92A) vaccine reveals a cascade of structural rearrangements located in three loop regions essential for binding the alpha subunit of major histocompatibility complex class II (MHC-II) molecules. A comparison of hypothetical model complexes between SEA and the SEA triple mutant with MHC-II HLA-DR1 clearly shows disruption of key ionic and hydrophobic interactions necessary for forming the complex. Extensive dislocation of the disulfide loop in particular interferes with MHC-IIalpha binding. The triple-mutant structure provides new insights into the loss of superantigenicity and toxicity of an engineered superantigen and provides a basis for further design of enterotoxin vaccines.

Surgical glove perforation in cardiac surgery

BACKGROUND

Recently, concern for the protection of health care employees and health care recipients has led to increasing awareness of transmitted infections. Sterile surgical gloves were tested to determine the incidence of perforations after being worn during procedures commonly performed by cardiac surgeons.

MATERIAL AND METHODS

In a prospective study conducted from January 15, 2000 through February 15, 2000, 953 gloves worn during cardiac surgery were evaluated for punctures. Pairs of sterile latex surgical gloves were collected over a period of one month. Routine tasks included mainly bypass and valve surgery. Impermeability was tested by means of a water retention test according to European standard EN 455 Part 1 performed on 954 (Manufix, Hartmann, Germany) latex gloves. A control group of 50 unused gloves was also evaluated for the presence of spontaneous leakage. Gloves were separated according to whether the wearer was an operator (254 gloves), first assistant (220 gloves), second assistant (272 gloves), or theatre nurse (207 gloves). Gloves with a known perforation occurring during the procedure were not included in the study.

RESULTS

There were no punctures in the 50 unused gloves. Punctures were detected in 66 of 254 (26.0 %) gloves used by operators, 49 of 220 (22.3 %) used by first assistants, 25 of 272 (9.2 %) used by second assistants, and 78 of 207 (37.7 %) used by theatre nurses. Some gloves had more than one puncture, accounting for the 244 holes detected (operators 75/244 = 30.7 %; first assistants 54/244 = 22.1 %; second assistants 28/244 = 11.5 %; theatre nurses 87/244 = 35.7 %). Sites of scalpel and suture needle injuries were most commonly the thumb (27.3 %) and pointer finger (42.1 %) of the non-dominant hand, followed by, in descending order: middle finger (10.2 %), other fingers (15.7 %), palm (3.8 %) and back of the hand (0.9 %).

CONCLUSION

The number of punctures that occur during cardiac operations is obviously higher than has so far been assumed. Therefore, cardiac surgeons should consider the incidence of unknown glove perforations when planning surgery in patients with infectious diseases.

Alzheimer's disease in the UK: comparative evidence on cost of illness and volume of health services research funding

OBJECTIVE

To review the economic cost of Alzheimer's disease, to determine the level of research expenditure directed at this illness and to make comparisons with cancer, stroke and heart disease.

METHOD

A literature search of cost-of-illness studies was conducted and major funders of research were contacted. Cost-of-illness estimates were updated and adjusted to enable comparability across the four disease areas.

RESULTS

The direct costs of Alzheimer's disease were estimated to be between 7.06 billion pounds sterling and 14.93 billion pounds sterling , which was substantially greater than stroke (3.2 billion pounds sterling), heart disease (4.05 billion pounds sterling ) and cancer (1.6 billion pounds sterling excluding informal care costs). Research expenditure on Alzheimer's disease was 57% of that on stroke, 10% of that on heart disease and 3% of that on cancer.

DISCUSSION

Alzheimer's disease imposes a high economic burden. However, spending on research is disproportionately low compared with spending on other major illnesses. In the light of these two findings we recommend further discussion of the distribution of public funding for research into this disease.

Movement and change: independent sector domiciliary care providers between 1995 and 1999

Promoting the development of a flourishing independent sector alongside good quality public services was a key objective of the community care reforms of the last decade. This paper charts some of the ways the independent domiciliary care sector is changing, as local authorities shift the balance of their provision toward independent sector providers and away from a reliance on in-house services. Two surveys of independent domiciliary care providers were carried out in 1995 and 1999. The aims of the studies were to describe the main features of provider organisations, such as size of business, client group and funding sources; to examine the nature of provider motivations and their past and future plans; to consider how local authorities manage the supply side of social care markets; and to examine the effects on providers of the development of the mixed economy. The first survey in 1995 was conducted in eight local authority areas, which by 1999 had increased to 11 because of the creation of three new unitary authorities. The findings are based on 261 postal surveys together with 111 interviews between the two studies. The research illustrates a domiciliary care market that is still relatively young with many small but growing businesses. There are considerable differences in the split between in-house and independent sector services in individual authorities and a common perception among independent providers that in-house services receive favourable treatment and conditions. Spot or call-off contracts continue to be the most common form of contract although there are moves toward greater levels of guaranteed service and more sophisticated patterns of contracting arrangements. There remains an ongoing need to share information between local authorities and independent providers so that good working relationships can develop with proven and competent providers.

Familial occurrence of tardive dyskinesia

OBJECTIVE

Familial occurrence of tardive dyskinesia (TD) and schizophrenia has been hypothesized to confer risk to the development of TD. We investigated these hypotheses in a large patient sample applying standardized methods for phenotype characterization.

METHOD

Two hundred and twenty-two patients with a diagnosis of schizophrenia or schizoaffective disorder were assessed for TD and for family history of schizophrenia or schizoaffective disorder. Thirty-nine patients had 40 affected first-degree family members, one patient having two first-degree relatives. Of these, 17 pairs and one triplet were personally examined.

RESULTS

1) There was a tendency for TD in the affected relatives to be associated with the TD status of the index-patient; this finding was unrelated to age and doses of neuroleptic medication. 2) No association between a family history of schizophrenia or schizoaffective disorder and TD was found.

CONCLUSION

A family history of TD might represent a risk factor for TD, whereas a family history of schizophrenia does not.

Reconstructing parental genotypes when testing for linkage in the presence of association

Various family-based association methods have recently been proposed that allow testing for linkage in the presence of linkage disequilibrium between a marker and a disease even if there is only incomplete parental-genotype information. For some families, it may be possible to reconstruct missing parental genotypes from the genotypes of their offspring. Treating such a reconstructed family as if parental genotypes have been typed, however, can introduce bias. The reconstruction-combined transmission/disequilibrium test (RC-TDT) and its X-chromosomal counterpart, XRC-TDT, employ parental-genotype reconstruction and correct for the biases involved in this reconstruction without relying on population marker allele frequencies. For the two tests, exact P values can be obtained by numerically calculating the convolution of the null distributions corresponding to the families in the sample.

Home treatment for mental health problems: a systematic review

OBJECTIVE

This review investigates the effectiveness of 'home treatment' for mental health problems in terms of hospitalisation and cost-effectiveness. For the purposes of this review, 'home treatment' is defined as a service that enables the patient to be treated outside hospital as far as possible and remain in their usual place of residence. METHODS - SYSTEMATIC LITERATURE SEARCH: 'Home treatment' excluded studies focused on day, residential and foster care. The review was based on Cochrane methodology, but non-randomised studies were included if they compared two services; these were only analysed if they provided evidence of the groups' baseline clinical comparability. METHODS - REVIEW OF ECONOMIC EVALUATIONS: Economic evaluations among the studies found were reviewed against established criteria. METHODS - IDENTIFICATION OF SERVICE COMPONENTS: A three-round Delphi exercise ascertained the degree of consensus among expert psychiatrists concerning the important components of community-based services that enable them to treat patients outside hospital. The identified components were used to construct the follow-up questionnaire. METHODS - FOLLOW-UP OF AUTHORS: As a supplement to the information available in the papers, authors of all the studies were followed up for data on service components, sustainability of programmes and service utilisation. METHODS - DATA ANALYSIS: The outcome measure was mean days in hospital per patient per month over the follow-up period. (1) Comparative analysis - compared experimental to control services. It analysed all studies with available data, divided into 'inpatient-control' and 'community-control' studies, and tested for associations between service components and difference in hospital days. (2) Experimental services analysis - analysed only experimental service data and tested for associations between service components and hospital days. RESULTS - SYSTEMATIC LITERATURE SEARCH: A total of 91 studies were found, conducted over a 30-year period. The majority (87) focused on people with psychotic disorders. RESULTS - REVIEW OF ECONOMIC EVALUATIONS: Only 22 studies included economic evaluations. They provided little conclusive evidence about cost-effectiveness because of problems with the heterogeneity of services, sample size, outcome measures and quality of analysis. RESULTS - DELPHI EXERCISE: In all, 16 items were rated as 'essential', falling into six categories: home environment; skill-mix; psychiatrist involvement; service management; caseload size; and health/social care integration. There was consensus that caseloads under 25 and flexible working hours over 7 days were important, but little support for caseloads under 15 or for 24-hour services, and consensus that home visiting was essential, but not on teams being 'explicitly dedicated' to home treatment. RESULTS - RESPONSE TO FOLLOW-UP: A total of 60% of authors responded, supplying data on service components and hospital days in most cases. Other service utilisation data were far less readily available. RESULTS - SERVICE CHARACTERISATION AND CLASSIFICATION: The services were homogeneous in terms of 'home treatment function' but fairly heterogeneous in terms of other components. There was some evidence for a group of services that were multidisciplinary, had psychiatrists as integrated team members, had smaller caseloads, visited patients at home regularly and took responsibility for both health and social care. This was not a cohesive group, however. RESULTS - SUSTAINABILITY OF SERVICES: The sustainability of home treatment services was modest: less than half the services whose authors responded were still identifiable. Services were more likely to be operational if the study had found them to reduce hospitalisation significantly. RESULTS - META-ANALYSIS: Meta-analysis with heterogeneous studies is problematic. The evidence base for the effectiveness of services identifiable as 'home treatment' was not strong. Within the 'inpatient-control' study group, the mean reduction in hospitalisation was 5 days per patient per month (for 1-year studies only). No statistical significance could be measured for this result. For 'community-control' studies, the reduction in hospitalisation was negligible. Moreover, the heterogeneity of control services, the wide range of outcome measures and the limited availability of data might have confounded the analysis. Regularly visiting at home and dual responsibility for health and social care were associated with reduced hospitalisation. Evidence for other components was inconclusive. Few conclusions could be drawn from the analysis of service utilisation data. RESULTS - LOCATION: Studies were predominately from the USA and UK, more of them being from the USA. North American studies found a reduction in hospitalisation of 1 day per patient per month more than European studies. North American and European services differed on some service components, but this was unlikely to account for this finding, particularly as no difference was found in their experimental service results. CONCLUSIONS - STATE OF RESEARCH: There is a clear need for further studies, particularly in the UK. The benefit of home treatment over admission in terms of days in hospital was clear, but over other community-based alternatives was inconclusive. CONCLUSIONS - NON-RANDOMISED STUDIES: Difficulties in systematically searching for non-randomised studies may have contributed to the smaller number of such studies found (35, compared with 56 randomised controlled trials). This imbalance was compounded by a relatively poor response rate from non-randomised controlled trial authors. Including them in the analysis had little effect. CONCLUSIONS - LIMITATIONS OF THIS REVIEW: A broad area was reviewed in order to avoid the problem of analysing by service label. While reviews of narrower areas may risk implying a homogeneity of the services that is unwarranted, the current strategy has the drawback that the studies cover a range of heterogeneous services. The poor definition of control services, however, is ubiquitous in this field, however reviewed areas are defined. Inclusion of mean data for which no standard deviations were available was problematic in that it prevented measuring the significance of the main findings. The lack of availability of this data, however, is an important finding, demonstrating the difficulty in seeking certainty in this area. Only days in hospital and cost-effectiveness were analysed here. The range and lack of uniformity of measures used in this field made meta-analysis of other outcomes impossible. It should be noted, however, that the findings pertain to these aspects alone. The Delphi exercise reported here was limited in being conducted only with psychiatrists, rather than a multidisciplinary panel. Its findings were used as a framework for the follow-up and analysis. Their possible bias should be borne in mind when considering them as findings in themselves. CONCLUSIONS - IMPLICATIONS FOR CLINICIANS: The evidence base for home treatment compared with other community-based services is not strong, although it does show that home treatment reduces days spent in hospital compared with inpatient treatment. There is evidence that visiting patients at home regularly and taking responsibility for both health and social care each reduce days in hospital. CONCLUSIONS - IMPLICATIONS FOR CONSUMERS: Services that visit patients at home regularly and those that take responsibility for both health and social care are likely to reduce time spent in hospital. Psychiatrists surveyed in this review also considered support for carers to be essential. The evidence from this review, however, was that few services currently have protocols for meeting carers' needs. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH AND COMMISSIONERS: A centrally coordinated research strategy, with attention to study design, is recommended. Studies should include economic evaluations that report health and social service utilisation. Service components should be collected and reported for both experimental and control services. Studies should be designed with adequate power and longer durations of follow-up and use comparable outcome measures to facilitate meta-analysis. Research protocols should be adhered to throughout the studies. It may be advisable that independent researchers conduct studies in future. It is no longer recommended that home treatment be tested against inpatient care, or that small, localised studies replicate existing, more highly powered studies.

Quality and costs of supported living residences and group homes in the United Kingdom

Information was collected on 63 adults in supported living residences, 55 adults in small group homes, and 152 adults in large group homes. Results indicated that (a) there were no statistically significant differences in service costs once these had been adjusted to take account of participant characteristics; (b) compared with participants living in small group homes, those in supported living residences had greater choice, participated in more community-based activities, experienced fewer scheduled activities, were more likely to have had their home vandalized, and were considered at greater risk of exploitation; (c) compared with participants living in large group homes, those in small group homes had larger social networks, more people in their social networks who were not staff, not family, and did not have mental retardation. These residents were considered at less risk of abuse.

Time costs of caring for children with severe disabilities compared with caring for children without disabilities

To assess time costs of caring for children with severe disabilities in the community compared to caring for children without disabilities, a diary- and questionnaire-based study was carried out. Sixteen complete data sets were obtained from families with children who have disabilities (mean age 8.7 years) and 31 complete data sets from families with normally developing children (mean age 4.9 years). Diagnoses in the study group included cerebral palsy, autism, Sanfillipo syndrome, lissencephaly, and osteogenesis imperfecta. Items of personal care per waking hour were significantly greater in children with disabilities than non-disabled children (p<0.001). In the study group, there was no correlation (r=-0.12) between age and frequency of care whereas a significant correlation was observed between degree of disability as measured by the Functional Independence Measure for children (WeeFIM) and frequency of care items (r=0.89). Twelve of the 16 mothers in the study group were not in paid employment. Twelve had little or no extended family support. Benefits awarded did not correlate with the degree of disability as measured by the WeeFIM (r=-0.11). Care needs of children with severe disabilities are significantly greater than those of non-disabled children and do not decrease with advancing age. Mothers of children with disabilities are unable to work outside the home because of these care needs. This brings the family income, even when benefits are included, to a level that is less than peer families with non-disabled children. A Functional Disability Score may help to achieve more appropriate allocation of state resources.

Financial cost of social exclusion: follow up study of antisocial children into adulthood

OBJECTIVES

To compare the cumulative costs of public services used through to adulthood by individuals with three levels of antisocial behaviour in childhood.

DESIGN

Costs applied to data of 10 year old children from the inner London longitudinal study selectively followed up to adulthood.

SETTING

Inner London borough.

PARTICIPANTS

142 individuals divided into three groups in childhood: no problems, conduct problems, and conduct disorder.

MAIN OUTCOME MEASURES

Costs in 1998 prices for public services (excluding private, voluntary agency, indirect, and personal costs) used over and above basic universal provision.

RESULTS

By age 28, costs for individuals with conduct disorder were 10.0 times higher than for those with no problems (95% confidence interval of bootstrap ratio 3.6 to 20.9) and 3.5 times higher than for those with conduct problems (1.7 to 6.2). Mean individual total costs were 70 019 pounds sterling for the conduct disorder group (bootstrap mean difference from no problem group 62 pound sterling; 898 pound sterling 22 692 pound sterling to 117 pound sterling) and 24 324 pound sterling (16 707 pound sterling; 6594 pound sterling to 28 149 pound sterling) for the conduct problem group, compared with 7423 pound sterling for the no problem group. In all groups crime incurred the greatest cost, followed by extra educational provision, foster and residential care, and state benefits; health costs were smaller. Parental social class had a relatively small effect on antisocial behaviour, and although substantial independent contributions came from being male, having a low reading age, and attending more than two primary schools, conduct disorder still predicted the greatest cost.

CONCLUSIONS

Antisocial behaviour in childhood is a major predictor of how much an individual will cost society. The cost is large and falls on many agencies, yet few agencies contribute to prevention, which could be cost effective.

Schizophrenia costs and treatment cost-effectiveness

OBJECTIVE

The paper sets out to summarize evidence on the costs of schizophrenia and on the cost-effectiveness of three broad treatment areas.

METHOD

Evidence from a number of countries was examined, both published and unpublished, and systematic reviews and meta-analyses were consulted.

RESULTS

The costs of schizophrenia are high and wide-ranging. They fall not only to health-care agencies but also to other parts of the public sector, to families, to sufferers themselves and to the wider society. However, there are interventions--a counselling intervention to address non-compliance with medication, family interventions to reduce levels of expressed emotion, and atypical antipsychotic drugs--that have been found to be not only effective (improving patient outcomes) but also appear to be cost-effective.

CONCLUSION

Resource constraints and policy pressures make it increasingly common for economic as well as clinical questions to be asked about new modes of treatment. This is the new reality of mental health practice. Reliable evidence is now available to address these economic questions and can be factored into decision-making processes.

Transcription factor HIF-1 is a necessary mediator of the pasteur effect in mammalian cells

The ability to respond to differential levels of oxygen is important to all respiring cells. The response to oxygen deficiency, or hypoxia, takes many forms and ranges from systemic adaptations to those that are cell autonomous. Perhaps the most ancient of the cell-autonomous adaptations to hypoxia is a metabolic one: the Pasteur effect, which includes decreased oxidative phosphorylation and an increase in anaerobic fermentation. Because anaerobic fermentation produces far less ATP than oxidative phosphorylation per molecule of glucose, increased activity of the glycolytic pathway is necessary to maintain free ATP levels in the hypoxic cell. Here, we present genetic and biochemical evidence that, in mammalian cells, this metabolic switch is regulated by the transcription factor HIF-1. As a result, cells lacking HIF-1alpha exhibit decreased growth rates during hypoxia, as well as decreased levels of lactic acid production and decreased acidosis. We show that this decrease in glycolytic capacity results in dramatically lowered free ATP levels in HIF-1alpha-deficient hypoxic cells. Thus, HIF-1 activation is an essential control element of the metabolic state during hypoxia; this requirement has important implications for the regulation of cell growth during development, angiogenesis, and vascular injury.

Structural phase transitions in CaC2

Pure CaC2, free of CaO impurities, was obtained by the reaction of elemental calcium with graphite at 1,070 K. By means of laboratory X-ray and synchrotron powder diffraction experiments, the phase diagram was investigated in the temperature range from 10 K to 823 K; this confirmed the literature data that reported the partial coexistence of up to four modifications. Aside from a cubic high-temperature modification CaC2 IV (Fm3m, Z = 4) and the well-known tetragonal modification CaC2 I (I4/mmm, Z = 2), a low-temperature modification CaC2 II (C2/c, Z =4) that crystallizes in the ThC2 structure type and a metastable modification CaC2 III (C2/m, Z = 4) that crystallizes in a new structure type were found. It was shown that phase transition temperatures as well as the relative amounts of the various CaC2 modifications depend upon the size of the crystallites, the thermal treatment. and the purity of the sample, as a comparison with technical CaC2 confirmed.

Mental health and foster carer training

AIMS

To evaluate the impact of training foster carers on children's emotional and behavioural functioning.

METHODS

In a randomised controlled trial in 17 Scottish local council areas, with immediate and nine month follow up, 182 children and their foster families were randomly allocated to either standard services alone or standard services plus extra training for foster carers on communication and attachment. Main outcome measures were child psychopathology, attachment disorder, self esteem, and cost of foster care.

RESULTS

Over 60% of children had measurable psychopathology at baseline. The training was perceived as beneficial by participants. Scores for parent reported psychopathology and attachment disorders decreased by around 5%, self esteem increased by 2%, and costs by 22% in the intervention group. Results were non-significant.

CONCLUSIONS

Despite being well received by foster carers, the training was not sufficient to make a useful impact on the high level of psychopathology. This group may warrant more intensive interventions.

Association analysis of the functional monoamine oxidase A gene promoter polymorphism in psychiatric disorders

Functional characterization studies revealed that transcriptional activity of the human monoamine oxidase A (MAOA) gene is modulated by a polymorphic repetitive sequence located approximately 1.2 kb upstream of the ATG codon. To investigate the possible influence of the allelic variants of the MAOA gene-linked polymorphic region (MAOA-LPR) on the genetic predisposition to psychiatric disorders, we have performed a case-control association study. 174 patients with affective disorders and 258 patients with schizophrenia according to DSM-IV, as well as 229 population controls were tested. Statistical analysis showed no significant differences in allele or genotype frequencies between control and patient groups. Our results suggest that there is no association between MAOA-LPR genotype and susceptibility to recurrent major depression, bipolar disorder, and schizophrenia in our population.

The economic impact of autism in Britain

Little is known about the economic impact of autism. This study estimated the economic consequences of autism in the United Kingdom, based on published evidence and on the reanalysis of data holdings at the Centre for the Economics of Mental Health (CEMH). With an assumed prevalence of 5 per 10,000, the annual societal cost for the UK was estimated to exceed ł1 billion. The lifetime cost for a person with autism exceeded ł2.4 million. The main costs were for living support and day activities. Family costs account for only 2.3 percent of the total cost, but a lack of relevant information limited our ability to estimate these costs. Minor improvements in life outcome for people with autism could substantially reduce costs over the lifetime.

The human dopamine transporter gene: the 5'-flanking region reveals five diallelic polymorphic sites in a Caucasian population sample

The 5'-flanking region of the human dopamine transporter (hDAT) was systematically screened for variants by single strand conformation analysis (SSCA) between -1586 and +97 basepair (bp) relative to the transcription start site. Five diallelic polymorphisms were found, which were shown to be due to single base substitutions: T-67A, G-660C, C-839T, C-1169G, T-1476G. In a population sample of 119 unrelated Caucasians, allele frequencies of the rarer allele were 47% for -67T, 3% for -660C, 45% for -839T, 50% for -1169G, and 8% for -1476G, respectively. Among 15 observed haplotypes, seven haplotypes collected a frequency of about 96% in our sample. T-67A, C-839T, C-1169G, T-1476G were related to potential transcriptional recognition sites. These findings and the occurrence of distinct haplotypes at the hDAT promoter locus in a Caucasian population sample make this region a promising target in the context of linkage and association studies in certain diseases.

Nonreplication of association between mu-opioid-receptor gene (OPRM1) A118G polymorphism and substance dependence

In the present investigation we hypothesized the A118G (Asn40Asp) polymorphism of the mu-opioid receptor gene (OPRM1) as a particular vulnerability factor for heroin and alcohol dependence. Therefore, we tested this hypothesis in two independent large samples by two different methods: a case-control sample (comprising n = 287 heroin and n = 221 alcohol study subjects versus n = 365 nondependent controls) and a family-controlled sample of 111 parent-offspring trios of heroin-dependent study subjects and 75 parent-offspring trios of alcohol-dependent study subjects to avoid stratification artifacts. In both patient samples and by both methods we were unable to corroborate the hypothesis of OPRM1 A118G polymorphism as a particular risk factor for any kind of substance dependence including opioid addiction. In addition, there was no significant association between the endophenotype of the individuals under study (e.g., comorbidity, severity of illness) and a particular genotype of OPRM1.

Association study of the low-activity allele of catechol-O-methyltransferase and alcoholism using a family-based approach

Catechol-O-methyltransferase (COMT) is a major component of the metabolic pathways of neurotransmitters such as dopamine, adrenaline, and noradrenaline. The activity of COMT is known to vary within the population; it exists in common high- and low-activity forms that are determined by a Val --> Met polymorphism at amino acid position 108/158 (in soluble or membrane-bound COMT). Recently, the low-activity allele was reported to contribute to the development of late-onset alcoholism in men. The present study extends this study by utilizing a family-based association approach, and by including individuals with early-onset alcoholism. Although no significant transmission disequilibrium was found in the overall sample of 70 parent/offspring trios (TDT = 1.43, P = 0.23), we observed a preferential transmission of the low-activity allele to patients with an early onset of disease (n = 32, TDT = 4.83, P = 0.028). Our results provide further evidence for an involvement of the COMT low-activity allele in the development of alcoholism and demonstrate the need for further studies in large samples of alcoholic patients.

Costs and characteristics of heavy inpatient service users in outer London

"Heavy users" is a new term often used to describe those who occupy a disproportionate number of psychiatric beds. In this study we identified the heaviest 10% (193) inpatient service users in one London borough over a 6 year period and compared these with a control group of 400 ordinary inpatient users. A weighting index was used to combine frequency of admission with duration. Heavy users were diagnostically and demographically similar to ordinary inpatient service users and only differed by their extensive use of services, about 3 times more than ordinary users in terms of health care costs, during the measured year. Their heavy use mainly depended on occupying hospital beds, and their use of outpatient, day patient and community services was relatively light.

Support for allelic association of a polymorphic site in the promoter region of the serotonin transporter gene with risk for alcohol dependence

OBJECTIVE

An association between the 5-HTTLPR short variant polymorphism in the promoter region of the serotonin transporter gene and risk for alcohol dependence has been reported from case-control studies that are, however, prone to chance findings related to artifacts of population structure. The authors sought additional evidence for this association from a family-based study.

METHOD

Ninety-two alcohol-dependent probands and their parents were tested for nonrandom transmission of alleles from heterozygous parents to affected probands.

RESULTS

Preferential transmission of the short allele was found (65 of 102 transmissions from heterozygous parents).

CONCLUSIONS

The results suggest allelic association between a variant in the promoter region of the serotonin transporter gene and the risk for alcohol dependence. However, it remains to be seen whether the functional properties of this variant are directly responsible for the increased risk to alcohol dependence.

A distinct gene close to the hairless locus on chromosome 8p underlies hereditary Marie Unna type hypotrichosis in a German family

BACKGROUND

Hypotrichosis of the Marie Unna type (HMU) is a rare autosomal dominant disorder characterized by male-pattern hair loss with childhood onset and anomalies of the hair shaft.

OBJECTIVES

We aimed to evaluate a number of chromosomal loci as possible candidate regions for HMU.

METHODS

A linkage analysis was performed in a large German family using microsatellite markers spanning candidate regions on chromosomes 8, 12 and 17.

RESULTS

We found that the HMU locus maps to chromosomal region 8p21 in a 13.01-cM interval between markers D8S1145 and D8S1771. This interval harbours the hairless gene (HR). Mutational analysis of HR on the genomic and transcript levels revealed no pathogenic mutation.

CONCLUSIONS

Our findings, together with a recent report of two unrelated families of Dutch and British origin, provide evidence for a hair growth regulatory gene distinct from HR in chromosomal region 8p21.

Differences in stability among the human apolipoprotein E isoforms determined by the amino-terminal domain

Denaturation by guanidine-HCl, urea, or heating was performed on the common isoforms of human apolipoprotein (apo) E (apoE2, apoE3, and apoE4) and their 22-kDa and 10-kDa fragments in order to investigate the effects of the cysteine/arginine interchanges at residues 112 and 158. Previous physical characterization of apoE3 established that apoE contains two domains, the 10-kDa carboxyl-terminal and 22-kDa amino-terminal domains, which unfold independently and exhibit large differences in stability. However, the physical properties of apoE2, apoE3, and apoE4 have not been compared before. Analysis by circular dichroism showed that the different isoforms have identical alpha-helical contents and guanidine-HCl denaturation confirmed that the two domains unfold independently in all three isoforms. However, guanidine-HCl, urea, and thermal denaturation showed differences in stability among the 22-kDa amino-terminal fragments of the apoE isoforms (apoE4 < apoE3 < apoE2). Furthermore, guanidine-HCl denaturation monitored by circular dichroism and fluorescence suggested the presence of a folding intermediate in apoE, most prominently in apoE4. Thus, these studies reveal that the major isoforms of apoE, which are associated with different pathological consequences, exhibit significant differences in stability.

Alternative strategies for stroke care: a prospective randomised controlled trial

BACKGROUND

Organised specialist care for stroke improves outcome, but the merits of different methods of organisation are in doubt. This study compares the efficacy of stroke unit with stroke team or domiciliary care.

METHODS

A single-blind, randomised, controlled trial was undertaken in 457 acute-stroke patients (average age 76 years, 48% women) randomly assigned to stroke unit, general wards with stroke team support, or domiciliary stroke care, within 72 h of stroke onset. Outcome was assessed at 3, 6, and 12 months. The primary outcome measure was death or institutionalisation at 12 months. Analyses were by intention to treat.

FINDINGS

152 patients were allocated to the stroke unit, 152 to stroke team, and 153 to domiciliary stroke care. 51 (34%) patients in the domiciliary group were admitted to hospital after randomisation. Mortality or institutionalisation at 1 year were lower in patients on a stroke unit than for those receiving care from a stroke team (21/152 [14%] vs 45/149 [30%]; p<0.001) or domiciliary care (21/152 [14%] vs 34/144 [24%]; p=0.03), mainly as a result of reduction in mortality. The proportion of patients alive without severe disability at 1 year was also significantly higher on the stroke unit compared with stroke team (129/152 [85%] vs 99/149 [66%]; p<0.001) or domiciliary care (129/152 [85%] vs 102/144 [71%]; p=0.002). These differences were present at 3 and 6 months after stroke.

INTERPRETATION

Stroke units are more effective than a specialist stroke team or specialist domiciliary care in reducing mortality, institutionalisation, and dependence after stroke.

Aims, outcome measures, study sites and patient sample. EPSILON Study 1. European Psychiatric Services: Inputs Linked to Outcome Domains and Needs

BACKGROUND

Cross-national research into the care of people with severe mental illnesses is hampered by a lack of standardised measures. The European Psychiatric Services: Inputs Linked to Outcome Domains and Needs (EPSILON) Study is a European Union funded project within the BIOMED-2 programme. The project aims to develop standardised instruments to facilitate future cross-national research.

AIMS

To describe the aims, outcome measures, study sites and patient samples of the EPSILON Study.

METHOD, RESULTS, CONCLUSIONS

See companion papers in this supplement.

Mapping of a gene for nonspecific X-linked mental retardation (MRX 75) to Xq24-q26

Nonspecific X-linked mental retardation is a heterogeneous condition consisting of nonsyndromal mental retardation in males. It is caused by mutation in one of several genes on the X chromosome (MRX genes). Here we report on the localization of a presumptive MRX gene to chromosomal region Xq24-q26 in a German family with nonspecific X-linked mental retardation (MRX 75, HUGO Human Gene Nomenclature Committee). Two point linkage analysis with 23 informative markers gave a lod score of 2.53 at theta = 0 for markers DXS425, DXS1254, DXS1114, and HPRT.

Psychiatric patients at greatest risk and in greatest need. Impact of the Supervision Register Policy

BACKGROUND

Mental health provider trusts in England were required in 1994 to establish local Supervision Registers of patients at risk.

AIMS

To identify the factors associated with registration, and obtain clinicians' views on its effectiveness.

METHOD

At a random sample of 14 trusts data were collected from case notes, key workers and responsible medical officers.

RESULTS

A sample of 133 registered patients were more disabled and had more extensive histories of violence and self-harm than 126 comparison patients on the upper tier of the Care Programme Approach (CPA). Those registered were a heterogeneous group. For some there was little evidence of risk. In most cases clinicians did not believe registration had improved care.

CONCLUSIONS

The Supervision Register policy has not resulted in the identification of a well-defined group. Its effectiveness is limited by the lack of operationalized measures of risk.

[Clinical characteristics of patients with tardive dyskinesias]

Although there is a great number of studies on the relationship between tardive dyskinesia and patient characteristics, too often their validity is impaired by the lack of operationalized criteria for the description of patients and signs. Reliable phenotyping is of utmost importance for linking clinical data with data from methods in neurobiology or molecular genetics. 241 patients with the DSM IV diagnosis "schizophrenia" or "schizoaffective disorder" were examined with the instruments SADS-L, OPCRIT, BPRS and PANSS. Motor phenomena were analyzed on 2 separate days within 3 months with the scales TDRS, AIMS, SAS, BAS. Tardive dyskinesia was diagnosed following the research criteria of Schooler and Kane. Lifetime medication with neuroleptics and anticholinergic drugs was assessed quantitatively.

RESULTS

97 out of 233 patients (= 41.6%) displayed persistent tardive dyskinesia. In univariate analysis, significant associations were found between tardive dyskinesia and the following independent variables (higher values means greater risk): Age (p = 0.0001), years from onset of the disorder (p = 0.001), total length of stay in hospital (p = 0.001), PANSS (single scales and sum score) (p = 0.0001), total amount of neuroleptics expressed as CPZ equivalents (p = 0.004). Logistic regression analysis showed that only the variables "age" and "negative symptoms" expressed as score on the PANSS negative subscale showed an association with tardive dyskinesia that could not be explained by covariation with other variables. The same results were found when, instead of the dichotomous variable "tardive dyskinesia yes/no" the associations with the TDRS score were analyzed. Future research should aim to approach the neurobiological correlates of "age" and "negative symptoms" in relationship to tardive dyskinesia.

Susceptibility for alcoholism: DRD4 exon III polymorphism: a case-control and a family-based association approach

Abstract The present investigation explored whether the 7-repeat allele of the exon III polymorphism in the dopamine D4 receptor gene confers to susceptibility of alcoholism. Using a classical case-control approach we first compared DRD4 exon III VNTR frequencies between alcoholics and ethnically matched controls (sample I). Secondly, we applied a family-based association approach in an independent parent-offspring sample of alcoholics (sample II). All patients underwent an inpatient treatment for alcohol detoxification: sample I comprised 218 alcoholics and 197 ethnically matched controls, sample II included 76 alcoholics plus their biological parents. A higher proportion of addicted individuals in sample I revealed the 7-repeat allele compared to the control sample yielding an odds ratio (OR) of 1.43 (individuals homozygous for 7-repeat allele) and an OR of 1.69 (homozygous and heterozygous 7-repeat allele individuals together). However, we failed to detect preferential transmission from parents to offspring of either the 7-repeat allele or the long alleles (5-7 repeats) of the DRD4 exon III VNTR in the family-based association approach (sample II). The impact of the DRD4 exon III polymorphism on susceptibility to addictive behaviour putatively plays only a minor role in our sample of alcohol-dependent patients, since we were not able to replicate our findings by the family-based association approach. However, a larger sample size by the family-based approach would be needed (approximately > 300 parent-offspring trios) to definitely corroborate or reject the findings from our case-control sample.

The "possible triangle" test for extreme discordant sib pairs

For the analysis of quantitative traits in nuclear families, extreme discordant sib pairs proved to be more powerful than unselected sib pairs. Here, we present a test that makes use of selected pairs and, in addition, restricts the parameters of the identical-by-descent distribution analogously to the "possible triangle" for affected sib pairs. In the Problem 2A data, extreme discordant sib pairs are selected. The analysis allowed the detection of most simulated major genes.

Association study of the tryptophan hydroxylase gene and bipolar affective disorder using family-based internal controls

The tryptophan hydroxylase (TPH) gene encodes for the rate-limiting enzyme of the serotonin metabolism and, therefore, has to be considered a major candidate for association studies in affective disorders. Recently, an association between this gene and bipolar affective disorder has been reported in a French population. We sought to replicate this finding in a German sample. Allele frequencies of a biallelic polymorphism (A218C) of the TPH gene were determined in 95 bipolar I patients and their parents. Preferential transmission of alleles from heterozygous parents to bipolar offspring was tested with the "transmission disequilibrium test" (TDT), which eliminates the contribution of population stratification to an association finding. Our sample yielded a power >90% to detect the originally reported effect. Neither allele 218A nor allele 218C were preferentially transmitted from heterozygous parents to bipolar offspring. Our results, therefore, do not support the hypothesis that the TPH gene is involved in the etiology of bipolar disorder.

Linkage and family-based association study of schizophrenia and the synapsin III locus that maps to chromosome 22q13

The human synapsin III gene (synapsin III) is a member of a neuron-specific phosphoprotein gene family involved in short-term neurotransmitter release. We mapped synapsin III to chromosomal region 22q13 (13.1-13.31) by fluorescence in situ hybridization, a region that has been identified as a potential schizophrenia susceptibility locus. The dinucleotide repeat marker D22S280 located in intron 5 of synapsin III was genotyped in a linkage and family-based association study to assess the role of the synapsin III locus in the etiology of schizophrenia. In 12 pedigrees with periodic catatonia comprising 135 individuals, we found exclusion of linkage of marker D22S280 using lod score analysis with autosomal dominant/recessive models as well as affected only LOD score methods with dominant/recessive models. In a family-based association study of 61 unrelated parent-offspring trios with schizophrenia (according to the the Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM-IV, American Psychiatric Association, 1994]), we found no association of individual D22S280 alleles to disease. Results of a multiallelic transmission/disequilibrium test (TDT(max) = 3.00; P = 0.55) challenged the possibility that D22S280 alleles appear with DSM-IV schizophrenia more frequently than expected. In addition, no evidence for gender differences or parent-of-origin effects were found. Thus, the synapsin III locus at chromosome 22q13 is not likely to contain a schizophrenia susceptibility gene.

Resonant X-ray diffraction using high-resolution image-plate data

The experimental setup for the collection of synchrotron X-ray powder diffraction data from samples with high absorption (μR> 10) is described. It consists of a combination of a vacuum chamber with an image-plate system. A numerical absorption correction for the applied geometry has been derived and the data were corrected accordingly. Values forf ′(Er) andf ′′(Er) were refined from eight measurements on Er5Re2O12above and below the ErLIIIabsorption edge. Successful refinement of the crystallographic data has verified the high quality of the collected intensities.

Conformational flexibility in the apolipoprotein E amino-terminal domain structure determined from three new crystal forms: implications for lipid binding

An amino-terminal fragment of human apolipoprotein E3 (residues 1-165) has been expressed and crystallized in three different crystal forms under similar crystallization conditions. One crystal form has nearly identical cell dimensions to the previously reported orthorhombic (P2(1)2(1)2(1)) crystal form of the amino-terminal 22 kDa fragment of apolipoprotein E (residues 1-191). A second orthorhombic crystal form (P2(1)2(1)2(1) with cell dimensions differing from the first form) and a trigonal (P3(1)21) crystal form were also characterized. The structures of the first orthorhombic and the trigonal form were determined by seleno-methionine multiwavelength anomalous dispersion, and the structure of the second orthorhombic form was determined by molecular replacement using the structure from the trigonal form as a search model. A combination of modern experimental and computational techniques provided high-quality electron-density maps, which revealed new features of the apolipoprotein E structure, including an unambiguously traced loop connecting helices 2 and 3 in the four-helix bundle and a number of multiconformation side chains. The three crystal forms contain a common intermolecular, antiparallel packing arrangement. The electrostatic complimentarity observed in this antiparallel packing resembles the interaction of apolipoprotein E with the monoclonal antibody 2E8 and the low density lipoprotein receptor. Superposition of the model structures from all three crystal forms reveals flexibility and pronounced kinks in helices near one end of the four-helix bundle. This mobility at one end of the molecule provides new insights into the structural changes in apolipoprotein E that occur with lipid association.