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Chris Evans

Publications and source records attributed to Chris Evans.

18 recordsLinked to original sources
PubMed2006

Pooled genome linkage scan of aggressive prostate cancer: results from the International Consortium for Prostate Cancer Genetics.

While it is widely appreciated that prostate cancers vary substantially in their propensity to progress to a life-threatening stage, the molecular events responsible for this progression have not been identified. Understanding these molecular mechanisms could provide important prognostic information relevant to more effective clinical management of this heterogeneous cancer. Hence, through genetic linkage analyses, we examined the hypothesis that the tendency to develop aggressive prostate cancer may have an important genetic component. Starting with 1,233 familial prostate cancer families with genome scan data available from the International Consortium for Prostate Cancer Genetics, we selected those that had at least three members with the phenotype of clinically aggressive prostate cancer, as defined by either high tumor grade and/or stage, resulting in 166 pedigrees (13%). Genome-wide linkage data were then pooled to perform a combined linkage analysis for these families. Linkage signals reaching a suggestive level of significance were found on chromosomes 6p22.3 (LOD = 3.0), 11q14.1-14.3 (LOD = 2.4), and 20p11.21-q11.21 (LOD = 2.5). For chromosome 11, stronger evidence of linkage (LOD = 3.3) was observed among pedigrees with an average at diagnosis of 65 years or younger. Other chromosomes that showed evidence for heterogeneity in linkage across strata were chromosome 7, with the strongest linkage signal among pedigrees without male-to-male disease transmission (7q21.11, LOD = 4.1), and chromosome 21, with the strongest linkage signal among pedigrees that had African American ancestry (21q22.13-22.3; LOD = 3.2). Our findings suggest several regions that may contain genes which, when mutated, predispose men to develop a more aggressive prostate cancer phenotype. This provides a basis for attempts to identify these genes, with potential clinical utility for men with aggressive prostate cancer and their relatives.

Black or African American↗
PubMed2006

Dose-effect relations and responsive regulation of treatment duration: the good enough level.

This study examined rates of improvement in psychotherapy as a function of the number of sessions attended. The clients (N=1,868; 73.1% female; 92.4% White; average age=40), who were seen for a variety of problems in routine primary care mental health practices, attended 1 to 12 sessions, had planned endings, and completed the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) at the beginning and end of their treatment. The percentage of clients achieving reliable and clinically significant improvement (RCSI) on the CORE-OM did not increase with number of sessions attended. Among clients who began treatment above the CORE-OM clinical cutoff (n=1,472), the RCSI rate ranged from 88% for clients who attended 1 session down to 62% for clients who attended 12 sessions (r=-.91). Previously reported negatively accelerating aggregate curves may reflect progressive ending of treatment by clients who had achieved a good enough level of improvement.

Adaptation, Psychological↗
PubMed2006

Dimensions of variation on the CORE-OM.

BACKGROUND: The Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) is a self-report measure comprising 28 items tapping three domains; subjective well-being, psychological problems and functioning. In addition to the potential theoretical value of the domains for operationalizing the phase model of psychotherapy, when consulted, managers and clinicians considered the distinction between problems and functioning important for assessing case-mix and clinical outcomes. A further domain comprising six items was included to indicate possible risk. Subsequent analysis has suggested an alternative structure for CORE-OM with factors for risk and positively and negatively worded items (Evans et al., 2002). METHODS: This study compares models for the interpersonal factor structure in data from the CORE-OM in 2,140 patients receiving psychological therapy in the UK. RESULTS: A multi-method, multi-trait, nested factors solution accounted optimally for the CORE-OM item covariance, with a first-order general factor latent and residualized first-order factors of subjective well-being, psychological problems, functioning and risk and with positively and negatively worded methods factors. The general factor was labelled psychological distress. Scale quality for CORE-OM, using a scoring method in which non-risk items are treated as a single scale and risk items as a second scale is satisfactory. IMPLICATIONS: The CORE-OM has a complex factor structure and may be best scored as 2 scales for risk and psychological distress. The distinct measurement of psychological problems and functioning is problematic, partly because many patients receiving out-patient psychological therapies and counselling services function relatively well in comparison with patients receiving general psychiatric services. In addition, a clear distinction between self-report scales for these variables is overshadowed by their common variance with a general factor for psychological distress. An alternative strategy for operationalizing this distinction is proposed.

Adult↗
PubMed2005

A combined genomewide linkage scan of 1,233 families for prostate cancer-susceptibility genes conducted by the international consortium for prostate cancer genetics.

Evidence of the existence of major prostate cancer (PC)-susceptibility genes has been provided by multiple segregation analyses. Although genomewide screens have been performed in over a dozen independent studies, few chromosomal regions have been consistently identified as regions of interest. One of the major difficulties is genetic heterogeneity, possibly due to multiple, incompletely penetrant PC-susceptibility genes. In this study, we explored two approaches to overcome this difficulty, in an analysis of a large number of families with PC in the International Consortium for Prostate Cancer Genetics (ICPCG). One approach was to combine linkage data from a total of 1,233 families to increase the statistical power for detecting linkage. Using parametric (dominant and recessive) and nonparametric analyses, we identified five regions with "suggestive" linkage (LOD score >1.86): 5q12, 8p21, 15q11, 17q21, and 22q12. The second approach was to focus on subsets of families that are more likely to segregate highly penetrant mutations, including families with large numbers of affected individuals or early age at diagnosis. Stronger evidence of linkage in several regions was identified, including a "significant" linkage at 22q12, with a LOD score of 3.57, and five suggestive linkages (1q25, 8q13, 13q14, 16p13, and 17q21) in 269 families with at least five affected members. In addition, four additional suggestive linkages (3p24, 5q35, 11q22, and Xq12) were found in 606 families with mean age at diagnosis of < or = 65 years. Although it is difficult to determine the true statistical significance of these findings, a conservative interpretation of these results would be that if major PC-susceptibility genes do exist, they are most likely located in the regions generating suggestive or significant linkage signals in this large study.

Aged↗
PubMed2005

Predicting change for individual psychotherapy clients on the basis of their nearest neighbors.

This study extended client-focused research by using the nearest neighbor (NN) approach, a client-specific sampling and prediction strategy derived from research on alpine avalanches. Psychotherapy clients (N=203) seen in routine practice settings in the United Kingdom completed a battery of intake measures and then completed symptom intensity ratings before each session. Forecasts of each client's rate of change and session-by-session variability were computed on the basis of that client's NNs (n=10-50 in different comparisons). Alternative forecasts used linear or log-linear slopes and were compared with an alternative prediction strategy. Results showed that the NN approach was superior to the alternative model in predicting rate of change, though the advantage was less clear for predicting variability.

Adolescent↗
PubMed2004

Motivating factors for male forensic patients with personality disorder.

INTRODUCTION: Treatability is currently a crucial component for detention under the Mental Health Act (England and Wales) for the Psychopathic Disorder (personality disorder) classification and there is continuing debate about the nature and assessment of treatability of individuals with personality disorder. Previous research has identified motivation to engage in treatment as a significant factor in the assessment of treatability; however, motivation is not a static predictor but a state of readiness or eagerness to change, which may fluctuate from one time or situation to another. While previous studies have explored factors within the individual that are used to assess treatability, this study aims to explore what, if any, aspects of an inpatient forensic setting influence patients' motivation to engage in treatment. METHOD: The study examines patients' experiences of engaging in treatment in an inpatient forensic Personality Disorder Directorate using a qualitative approach to identify possible service-, ward- and therapist-level influences on patients' motivation to engage. RESULTS: Preliminary categories were identified across the data, including: support, treatment, safety, external belief, belonging, internal motivation and therapeutic relationship. CONCLUSIONS: Implications for the service are identified and areas for further qualitative exploration are highlighted.

Adult↗
PubMed2004

Computer simulations improve university instructional laboratories.

Laboratory classes are commonplace and essential in biology departments but can sometimes be cumbersome, unreliable, and a drain on time and resources. As university intakes increase, pressure on budgets and staff time can often lead to reduction in practical class provision. Frequently, the ability to use laboratory equipment, mix solutions, and manipulate test animals are essential learning outcomes, and "wet" laboratory classes are thus appropriate. In others, however, interpretation and manipulation of the data are the primary learning outcomes, and here, computer-based simulations can provide a cheaper, easier, and less time- and labor-intensive alternative. We report the evaluation of two computer-based simulations of practical exercises: the first in chromosome analysis, the second in bioinformatics. Simulations can provide significant time savings to students (by a factor of four in our first case study) without affecting learning, as measured by performance in assessment. Moreover, under certain circumstances, performance can be improved by the use of simulations (by 7% in our second case study). We concluded that the introduction of these simulations can significantly enhance student learning where consideration of the learning outcomes indicates that it might be appropriate. In addition, they can offer significant benefits to teaching staff.

Biology↗
PubMed2003

Results of a genome-wide linkage analysis in prostate cancer families ascertained through the ACTANE consortium.

BACKGROUND: The aggregation of prostate cancer within families suggests a major inherited component to the disease. Genetic linkage studies have identified several chromosomal regions that may contain prostate cancer susceptibility loci, but none has been definitively implicated. METHODS: We performed a genome-wide linkage search based on 64 families, 63 with at least 3 cases of prostate cancer, ascertained in five countries. The majority of cases from these centers presented with clinically detected disease. Four hundred and one polymorphic markers were typed in 268 individuals. Multipoint heterogeneity analysis was conducted under three models of susceptibility; non-parametric analyses were also performed. RESULTS: Some weak evidence of linkage, under at least one of the genetic models, was observed to markers on chromosomes 2 (heterogeneity LOD (HLOD) = 1.15, P = 0.021), 3 (HLOD = 1.25, P = 0.016), 4 (HLOD = 1.28, P = 0.015), 5 (HLOD = 1.20, P = 0.019), 6 (HLOD = 1.41, P = 0.011), and 11 (HLOD = 1.24, P = 0.018), and in two regions on chromosome 18 (HLOD = 1.40, P = 0.011 and HLOD = 1.34, P = 0.013). There were no HLOD scores greater than 1.5 under any model, and no locus would be predicted to explain more than half of the genetic effect. No evidence in favor of linkage to previously suggested regions on chromosomes 1, 8, 17, 20, or X was found. CONCLUSIONS: Genetic susceptibility to prostate cancer is likely to be controlled by many loci, with no single gene explaining a large fraction of the familial risk. Pooling of results from all available genome scans is likely to be required to obtain definitive linkage results.

Adult↗
PubMed2003

Synthesis of biologically active canine CCK-58.

The carboxyl terminal octapeptide of cholecystokinin (CCK-8) has been hypothesized to account for the bioactivity of all the molecular forms of cholecystokinin. However, the physiological relevance of CCK-58 has not been rigorously examined because of the lack of sufficient amounts of the peptide and concerns about inactivation of natural peptides during their purification. Therefore, canine-sulfated CCK-58 was synthesized and conditions determined for its unblocking and purification that preserved the sulfated tyrosine. Synthetic CCK-58 was indistinguishable from natural CCK-58 by amino acid analysis and by mass spectrometry. Synthetic CCK-58 and CCK-8 have different patterns of pancreatic stimulation: both caused a dose-related increase in amylase release, while only CCK-58 stimulated bile-pancreatic output volume. Thus, CCK-58 and CCK-8 are biased agonists at the CCK-A receptor (they have distinct patterns of action mediated by the same receptor). Previous work has demonstrated that the identical carboxyl termini of CCK-8 and CCK-58 have different solution conformations. Taken together, the physiological and structural results support the hypothesis that different carboxyl terminal conformations of CCK-58 and CCK-8 alter the expression of their biological activity.

Amino Acids↗
PubMed2003

Regulated endocytosis of opioid receptors: cellular mechanisms and proposed roles in physiological adaptation to opiate drugs.

Opiate drugs such as morphine and heroin are among the most effective analgesics known. Prolonged or repeated administration of opiates produces adaptive changes in the nervous system that lead to reduced drug potency or efficacy (tolerance), as well as physiological withdrawal symptoms and behavioral manifestations such as craving when drug use is terminated (dependence). These adaptations limit the therapeutic utility of opiate drugs, particularly in the treatment of chronically painful conditions, and are thought to contribute to the highly addictive nature of opiates. For many years it has been proposed that physiological tolerance to opiate drugs is associated with a modification of the number or functional activity of opioid receptors in specific neurons. We now understand certain mechanisms of opioid receptor desensitization and endocytosis in considerable detail. However, the functional roles that these mechanisms play in the complex physiological adaptation of the intact nervous system to opiates are only beginning to be explored.

Adaptation, Physiological↗
PubMed2003

Recovery from acidification in European surface waters: a view to the future.

There is now overwhelming documentation of large-scale chemical recovery from surface water acidification in Europe, but to date there has been little documentation of biological recovery. Modelling studies based on current emission reduction plans in Europe indicate that there will be further chemical recovery. The uncertainties in these scenarios mainly relate to the future behavior of nitrogen in the ecosystem and the effects of climate change. Four major climate-related confounding factors that may influence the chemical and biological recovery process are: i) increased frequency and severity of sea-salt episodes; ii) increased frequency and severity of drought; iii) increased turnover of organic carbon; iv) increased mineralization of nitrogen. International cooperative work to abate acidification has so far been very successful, but there is still a long way to go, and many potential setbacks. It is essential that future development of water chemistry and aquatic biota in acidified waterbodies continue to be monitored in relation to further emission reductions of S and N and future effects of climate change.

Acid Rain↗
PubMed2002

Surface modification and patterning using low-energy ion beams: Si-O bond formation at the vacuum/adsorbate interface.

Modification of hydroxyl-terminated self-assembled monolayer (HO-SAM) surfaces by collision of low-energy (15 eV) hyperthermal Si(CH3)3+ ions is shown to lead to Si-O bond formation and terminal trimethylsilyl ether formation. Modification was verified by in situ mass spectrometry using chemical sputtering with CF3+ ions (70 eV), ex situ secondary ion mass spectrometric analysis (12 kV Ga+ primary ion beam), and through X-ray photoelectron spectroscopy by monitoring Si (2s). The nature of the surface modification was further established by analysis of synthetic SAM surfaces made up of mixtures of the trimethylsilyl-11-mercapto-1-undecane ether and various proportions of the hydroxyl-terminated mercaptan (11-mercapto-1-undecanol). These mixed surfaces, as well as the spectroscopic data, indicate that ca. 30% of the hydroxyl chains are covalently modified at saturation coverage. Analogous surface transformations are achieved using Si(CH3)2F+ and Si(CH3)2C6H5+.

Journal Article↗
PubMed2002

Silylation of an OH-terminated self-assembled monolayer surface through low-energy collisions of ions: a novel route to synthesis and patterning of surfaces.

Using a multi-sector ion-surface scattering mass spectrometer, reagent ions of the general form SiR(3) (+) were mass and energy selected and then made to collide with a hydroxy-terminated self-assembled monolayer (HO-SAM) surface at energies of approximately 15 eV. These ion-surface interactions result in covalent transformation of the terminal hydroxy groups at the surface into the corresponding silyl ethers due to Si--O bond formation. The modified surface was characterized in situ by chemical sputtering, a low-energy ion-surface scattering experiment. These data indicate that the ion-surface reactions have high yields (i.e. surface reactants converted to products). Surface reactions with Si(OCH(3))(3) (+), followed by chemical sputtering using CF(3) (+), yielded the reagent ion, Si(OCH(3))(3) (+), and several of its fragments. Other sputtered ions, namely SiH(OCH(3))(2)OH(2) (+) and SiH(2)(OCH(3))OH(2) (+), contain the newly formed Si--O bond and provide direct evidence for the covalent modification reaction. Chemical sputtering of modified surfaces, performed using CF(3) (+), was evaluated over a range of collision energies. The results showed that the energy transferred to the sputtered ions, as measured by their extent of fragmentation in the scattered ion mass spectra, was essentially independent of the collision energy of the projectile, thus pointing to the occurrence of reactive sputtering.A set of silyl cations, including SiBr(3) (+), Si(C(2)H(3))(3) (+) and Si(CH(3))(2)F(+), were similarly used to modify the HO-SAM surface at low collision energies. A reaction mechanism consisting of direct electrophilic attack by the cationic projectiles is supported by evidence of increased reactivity for these reagent ions with increases in the calculated positive charge at the electron-deficient silicon atom of each of these cations. In a sequential set of reactions, 12 eV deuterated trimethylsilyl cations, Si(CD(3))(3) (+), were used first as the reagent ions to modify covalently a HO-SAM surface. Subsequently, 70 eV SiCl(3) (+) ions were used to modify the surface further. In addition to yielding sputtered ions of the modified surface, SiCl(3) (+) reacted with both modified and unmodified groups on the surface, giving rise not only to such scattered product ions as SiCl(2)OH(+) and SiCl(2)H(+), but also to SiCl(2)CD(3) (+) and SiCl(2)D(+). This result demonstrates that selective, multi-step reactions can be performed at a surface through low-energy ionic collisions. Such processes are potentially useful for the construction of novel surfaces from a monolayer substrate and for chemical patterning of surfaces with functional groups.

Journal Article↗
PubMed2002

Towards a standardised brief outcome measure: psychometric properties and utility of the CORE-OM.

BACKGROUND: An acceptable, standardised outcome measure to assess efficacy and effectiveness is needed across multiple disciplines offering psychological therapies. AIMS: To present psychometric data on reliability, validity and sensitivity to change for the CORE-OM (Clinical Outcomes in Routine Evaluation--Outcome Measure). METHOD: A 34-item self-report instrument was-developed, with domains of subjective well-being, symptoms, function and risk. Analysis includes internal reliability, test-retest reliability, socio-demographic differences, exploratory principal-component analysis, correlations with other instruments, differences between clinical and non-clinical samples and assessment of change within a clinical group. RESULTS: Internal and test-retest reliability were good (0.75-0.95), as was convergent validity with seven other instruments, with large differences between clinical and non-clinical samples and good sensitivity to change. CONCLUSIONS: The CORE-OM is a reliable and valid instrument with good sensitivity to change. It is acceptable in a wide range of practice settings.

Adolescent↗
PubMed2002

Families of homicide victims: psychiatric responses and help-seeking.

The number of homicides in the UK is increasing: 850 homicides were recorded in England and Wales last year, but little is known about their impact on surviving family members. This study describes their psychological and social effects. Relatives seeking help from Victim Support were surveyed about their experiences, responses and help-seeking and asked to complete a number of psychological measures. Victim Support workers provided additional information. High levels of post-traumatic stress symptomatology and generalized distress were identified, as well as an increase in prescribed psychotropic medication. Other effects included increases in anger and irritability, cigarette consumption and loss of employment. However, few family members had been referred for professional treatment.

Adult↗
PubMed2002

The properties of self-report research measures: beyond psychometrics.

Self-report measures pertinent for personality disorder are widely used and many are available. Their relative merits are usually assessed on nomothetic psychometrics and acceptability to users is neglected. We report reactions of lay, patient and professional groups to the Personality Diagnostic Questionnaire (PDQ-IV); Millon Clinical Multiaxial Inventory (MCMI-III); the Borderline Syndrome Index (BSI); Rosenberg's Self-Esteem Scale (RSE) and the Social Functioning Questionnaire (SFQ). These were sent to 148 professionals, ex-patients and lay people for comment. Thirty-six per cent were returned. Pattern-coding by three raters revealed problematic themes across all measures, including inappropriate length, vague items and language, cultural assumptions and slang, state-bias and response-set. Measures can be depressing and upsetting for some participants (both patients and non-patients), hence administration of measures should be sensitive. Treatment may make people more self-aware, which may compromise validity for outcome research. This evaluation raises issues and concerns, which are missed in traditional psychometric evaluation.

Adolescent↗