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Biomedical subjects

G Dunn

Publications and source records attributed to G Dunn.

At least 73 records · Page 4Linked to original sources
PubMed1997

London-East Anglia randomised controlled trial of cognitive-behavioural therapy for psychosis. II: Predictors of outcome.

BACKGROUND: Despite growing evidence of the effectiveness of cognitive-behavioural therapy (CBT) for psychosis, typically only about 50% of patients show a positive response to treatment. This paper reports the first comprehensive investigation of factors which predict treatment outcome. METHOD: In a randomised controlled trial of CBT for medication-resistant psychosis (see Part I) measures were taken at baseline of demographic, clinical and cognitive variables. Changes over time were assessed on the Brief Psychiatric Rating Scale and the relationship between potential predictor variables and outcome was investigated using analysis of variance and covariance. RESULTS: A number of baseline variables were identified as predictors of good outcome in the CBT group. Key predictors were a response indicating cognitive flexibility concerning delusions (P = 0.005) and the number of recent admissions (P = 0.002). Outcome was less predictable in the control group and was not predicted by any cognitive variable. CONCLUSIONS: Good outcome is strongly predicted in patients with persistent delusions by a cognitive measure, while this was not the case in controls. Thus we argue that positive outcome in CBT is due in part to specific effects on delusional thinking.

Adult↗
PubMed1997

The discipline and literature of general practice.

In response to a review recently carried out by the Royal College of General Practitioners, the British Journal of General Practice is soon to be issued in a new and expanded format. While continuing to develop its primary role as a leading scientific journal of record, the journal will accommodate a monthly selection of integrated news, information and features. The editorial board welcomes the opportunities provided by these changes, but wishes to emphasize the continuing importance of general practice as a scientific discipline in its own right and to reaffirm its commitment to the publication of high-quality, peer-reviewed original research papers. It is hoped that the newlook journal will have a wide appeal. But, as the first-and still the foremost-journal of general practice in the world, it will continue to be a journal of record serving both its authors and the academic community worldwide.

Family Practice↗
PubMed1996

Sociodemographic and clinical variables as predictors of the diagnostic characteristics of first episodes of schizophrenia.

This paper examines the association of clinical and sociodemographic factors, including age and sex, with the diagnostic characteristics of first episodes of schizophrenia. The study included all patients with a first episode of schizophrenia who made contact with any of the public mental health services of the Autonomous Region of Cantabria in Northern Spain over a period of 2 years. Diagnostic characteristics were determined using the Spanish version of the Present State Examination (PSE-9), and the Scales for the Assessment of Positive and Negative Symptoms (SAPS and SANS, respectively). The study confirms that the onset of schizophrenia tends to occur earlier in men than in women. However, neither sex nor age of onset were found to be associated with the clinical and psychopathological characteristics of the patients as established by the PSE-CATEGO-ID system. Furthermore, no other factors were found to be associated with these diagnostic characteristics. Being female, having a family history of mental illness, and a poor premorbid adjustment were found to predict negative symptoms as defined by SANS/SAPS scales.

Adult↗
PubMed1996

Complex surveys.

Explore the source record for details and available documents.

Data Interpretation, Statistical↗
PubMed1996

Patterns of positive and negative symptoms in first episode schizophrenia.

BACKGROUND: The aim is to examine, in first episodes of schizophrenia, the appropriateness of the simple two-dimensional model of schizophrenia ('negative' and 'positive' dimensions) and more complex variants. METHOD: All patients with a first episode of schizophrenia who, over a two-year period, made contact with any of the public mental health services of the autonomous region of Cantabria in northern Spain were investigated. The psychiatric evaluation included, among other instruments, the Present State Examination (PSE-9), and the scales for the assessment of the 'positive' and 'negative' symptoms of schizophrenia (SAPS and SANS respectively). The dimensionality of the SAPS/SANS item scores and sub-scales was examined throughout the use of principal component analysis. RESULTS: The principal component solution that best fits the data obtained with the initial SANS/SAPS sub-scales reflects the existence of three different ('negative', 'positive', 'disorganisation') factors. The strategy adopted of repeating the analysis after extracting the principal components of the original sub-scales, revealed that although the nature and item composition of the initial 'negative' and 'disorganisation' factors were in general confirmed, the 'positive' dimension presented a more complex structure with at least two 'positive' ('Non-Paranoid' and 'Paranoid') independent factors. CONCLUSION: The psychopathological structure of the early stages of schizophrenia, as evaluated by the SANS/SAPS, is characterised by the presence of four dimensions: two 'positive', one 'negative' and one 'disorganisation'.

Adolescent↗
PubMed1996

Neuronal pattern correlates with the severity of human immunodeficiency virus-associated dementia complex. Usefulness of spatial pattern analysis in clinicopathological studies.

The spatial distributional pattern of neurons, in the superior frontal gyrus of 32 subjects who died of acquired immune deficiency syndrome, was examined. The patients were classified as nondemented, mildly demented, and severely demented, and some were treated with the anti-retroviral drug zidovudine. Spatial statistical techniques were employed to investigate the degree of clustering in the individual cases and various groups. We found that the cluster pattern of large and small neurons differed significantly with increasing severity of dementia but was not influenced by the duration of zidovudine treatment. We conclude that this is a sensitive technique for clinicopathological correlations and that the differences may result from loss of specific neuronal populations, which could determine the degree of dementia.

AIDS Dementia Complex↗
PubMed1995

Computerized brain tissue classification of magnetic resonance images: a new approach to the problem of partial volume artifact.

Due to the finite spatial resolution of digital magnetic resonance images of the brain, and the complexity of anatomical interfaces between brain regions of different tissue type, it is inevitable that some voxels will represent a mixture of two or three different tissue types. Outright assignment of such "bipartial" or "tripartial" voxels to one class or another is more problematic and less reliable than assignment of "full-volume" voxels, wholly representative of a single tissue type. We have developed a computerized system for brain tissue classification of dual echo MR data, which uses a polychotomous logistic model for discriminant analysis, combined with a Bayes allocation rule incorporating differential prior probabilities, and spatial connectivity tests, to assign each voxel in the image to one of four possible classes: gray matter, white matter, cerebrospinal fluid, or unclassified. The system supports automated volumetric analysis of segmented images, has low operational overheads, and compares favorably with previous multivariate or "multispectral" approaches to brain MR image segmentation in terms of both validity (bootstrap misclassification rate = 3.3%) and interoperator reliability (intra-class correlation coefficients for all three tissue classes > 0.9). We argue that these improvements in performance stem from better methodological management of the related problems of non-Normality of MR signal intensity values and partial volume artifact.

Artifacts↗
PubMed1995

Structural abnormalities of the brain in schizophrenia: sex differences in the Cantabria First Episode of Schizophrenia Study.

This paper examines structural brain abnormalities, as evaluated by the CT scan, in first episodes of schizophrenia and their association with sociodemographic, diagnostic and clinical variables. The investigation included all patients with a first episode of schizophrenia who, over a 2-year period, made contact with any of the public mental health services of the Autonomous Region of Cantabria in Northern Spain. Diagnostic and clinical characteristics were evaluated through the use of the Spanish version of the Present State Examination (PSE-9) and the Scales for the Assessment of Positive and Negative Symptoms (SANS and SAPS respectively). The study demonstrated the presence of structural brain abnormalities in this sample of first episode schizophrenics. These abnormalities were mainly expressed in the presence of larger VBR for schizophrenic patients than in the controls, these findings being more marked in women than in men. We failed to reveal, however, any evidence of an association of these brain abnormalities with diagnostic or clinical characteristics.

Adult↗
PubMed1995

Treatment in the narcoleptic syndrome: self assessment of the action of dexamphetamine and clomipramine.

Subjective evaluation of the effect of treatment of excessive daytime sleepiness (EDS) with dexamphetamine and of cataplexy with clomipramine was made in 124 subjects with the narcoleptic syndrome. Drug effects were evaluated by self-report of the propensity to EDS and cataplexy as determined by the Epworth Sleepiness Scale and a rating scale of anticipation-associated loss of postural motor tone during long-term therapy. The effects of dexamphetamine alone (60 subjects), clomipramine alone (16 subjects) and combined dexamphetamine-clomipramine treatment (48 subjects) were evaluated. Self-reports indicated that the propensity to EDS was reduced by approximately 20% by dexamphetamine (mean dosage 16 mg/24 h, range 5-60: mean treatment period 21 years, range 2-45). The propensity to cataplexy was reduced by 23% by clomipramine (mean dosage 64 mg/24 h, range 25-125: mean treatment period 14 years, range 1-24). Dexamphetamine alone, in addition to reducing the propensity to EDS also reduced the propensity to cataplexy. Clomipramine alone reduced cataplexy, but not EDS. Combined dexamphetamine-clomipramine treatment caused a reduction in the propensity to EDS and cataplexy of similar magnitude to that caused by dexamphetamine alone. Less than 10% of all subjects with the narcoleptic syndrome reported a daytime sleep propensity in the normal range whilst on dexamphetamine and no subject on clomipramine reported complete control of cataplexy. Long-term treatment with dexamphetamine was associated with weight increase more commonly than weight loss. Weight gain was reported by two-thirds of subjects taking clomipramine alone. Reports of weight loss were as common as reports of weight gain by subjects on combined dexamphetamine-clomipramine treatment. Constipation, dry mouth and impaired sexual function were reported by 25%, 38% and 19% (respectively) of subjects on clomipramine. This retrospective long-term self-report study investigated the propensity to, rather than the frequency of, episodes of EDS and cataplexy in subjects with the narcoleptic syndrome. This study suggests that long-term drug treatment in the narcoleptic syndrome results in only minor reduction in attack propensity, in contrast to the findings of many previous short term objective studies, which suggest 50-80% reduction in attack frequency. Major factors limiting response to dexamphetamine in the narcoleptic syndrome include physician prescription of sub-optimal drug dosages, and a low index between the limited therapeutic efficacy and frequent side-effects of this drug.

Journal Article↗
PubMed1995

Role of mutations G-480 and C-6203 in the attenuation phenotype of Sabin type 1 poliovirus.

Of the 55 point mutations which distinguish the type 1 poliovirus vaccine strain (Sabin 1) from its neurovirulent progenitor (P1/Mahoney), two have been strongly implicated by previous studies as determinants of the attenuation phenotype. A change of an A to a G at position 480, located within the 5' noncoding region, has been suggested to be the major attenuating mutation, analogous to the mutations at positions 481 and 472 in poliovirus types 2 and 3, respectively. In addition, the change of a U to a C at position 6203, resulting in an amino acid change in the polymerase protein 3D, has also been implicated as a determinant of attenuation, albeit to a lesser extent. To assess the contributions of these mutations to attenuation and temperature sensitivity, reciprocal changes were generated at these positions in infectious cDNA clones of Sabin 1 and P1/Mahoney. Assays in tissue culture and primates indicated that the two mutations make some contribution to the temperature sensitivity of the Sabin 1 strain but that neither is a strong determinant of attenuation.

Cell Line↗
PubMed1995

Screening for stratification in two-phase ('two-stage') epidemiological surveys.

Screening is undertaken not only for the purpose of giving therapeutic treatment to those among screen positive subjects found to be diagnosis positive, but it is also used in epidemiology as the first phase of multi-phase sampling designs. We review the use of such designs in epidemiology, and in psychiatric epidemiology in particular, focusing on two-phase or double sampling. We then compare a variety of approaches to the statistical analysis of data from such designs including the use of sampling weights, Gibbs sampling, full maximum likelihood for random effects logistic regression and a simple E-M algorithm for incomplete data. The methods are illustrated using data from a recent multi-phase study of psychiatric morbidity in northern Spain.

Humans↗
PubMed1995

A brief mental health outcome scale-reliability and validity of the Global Assessment of Functioning (GAF).

BACKGROUND: The Global Assessment of Functioning (GAF) is a quick and simple measure of overall psychological disturbance. However, there is little research on the reliability and validity of this measure in severely mentally ill populations. METHOD: Multidisciplinary keyworkers assessed 103 patients at monthly intervals over a 6-month period. Overall GAF scores were obtained, with additional separate ratings for symptoms and disability. These were compared with changes in antipsychotic medication and support needs over the same period. RESULTS: Satisfactory reliability was obtained for total GAF score and for symptom and disability measures, in spite of raters having only one brief training session. All GAF scores were associated with current support needs of patients. Symptom and disability scores were associated with changes in antipsychotic medication in the previous month. Only symptom score was associated with increases in antipsychotic medication at time of rating. CONCLUSION: GAF proved to be a reliable and, within the limits of the indicators used, a valid measure of psychiatric disturbance in our sample of the severely mentally ill. Differences in relationships between the three GAF scores and medication/support needs indicate the usefulness of obtaining all three scores for monitoring levels and type of psychiatric disturbance in this population.

Activities of Daily Living↗
PubMed1995

The Camberwell Assessment of Need: the validity and reliability of an instrument to assess the needs of people with severe mental illness.

BACKGROUND: People with severe mental illness often have a complex mixture of clinical and social needs. The Camberwell Assessment of Need (CAN) is a new instrument which has been designed to provide a comprehensive assessment of these needs. There are two versions of the instrument: the clinical version has been designed to be used by staff to plan patients' care; whereas the research version is primarily a mental health service evaluation tool. The CAN has been designed to assist local authorities to fulfil their statutory obligations under the National Health Service and Community Care Act 1990 to assess needs for community services. METHOD: A draft version of the instrument was designed by the authors. Modifications were made following comments from mental health experts and a patient survey. Patients (n = 49) and staff (n = 60) were then interviewed, using the amended version, to assess the inter-rater and test-retest reliability of the instrument. RESULTS: The mean number of needs identified per patient ranged from 7.55 to 8.64. Correlations of the inter-rater and test-retest reliability of the total number of needs identified by staff were 0.99 and 0.78 respectively. The percentage of complete agreement on individual items ranged from 100-81.6% (inter-rater) and 100-58.1% (test-retest). CONCLUSIONS: The study suggests that the CAN is a valid and reliable instrument for assessing the needs of people with severe mental illness. It is easily learnt by staff from a range of professional backgrounds, and a complete assessment took, on average, around 25 minutes.

Adult↗
PubMed1994

Effects of case management after severe head injury.

OBJECTIVES: To examine the effects of early case management for patients with severe head injury on outcome, family function, and provision of rehabilitation services. DESIGN: Prospective controlled unmatched non-randomised study for up to two years after injury. SETTING: Four district general hospitals and two university teaching hospitals, each with neurosurgical units, in east central, north, and north east London and its environs. SUBJECTS: 126 patients aged 16-60 recruited acutely and sequentially after severe head injury. All received standard rehabilitation services in each of the six hospitals and districts: case management was also provided for the 56 patients admitted to three of the hospitals. MAIN OUTCOME MEASURES: Standard measures of patients' physical and cognitive impairment; disability and handicap; and affective, behavioural, and social functioning and of relatives' affective and social functioning. Relatives' perception of burden; changes in patients' and relatives' housing, financial, vocational, recreational, and medical needs; and ongoing requirements for care and support; and the amount and type of paramedical input provided were assessed with structured questionnaires. RESULTS: For a given severity of injury, case management increased the chance and range of contact with inpatient and outpatient rehabilitation services. However, duration of contact was not increased by case management, and there was no demonstrable improvement in outcome in the case managed group. Any trends were in favour of the control group and could be accounted for by group differences in initial severity of injury. CONCLUSIONS: Widespread introduction of early case management of patients after severe head injury is not supported, and early case management is not a substitute for improvement in provision of skilled and specialist rehabilitation for patients.

Activities of Daily Living↗