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Biomedical subjects

G Dunn

Publications and source records attributed to G Dunn.

At least 19 recordsLinked to original sources
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

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

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↗
PubMed1994

Statistical methods for measuring outcomes.

This issue of the journal concerns promotion of the routine use of outcome measures in clinical practice; the purpose of this particular article, however, is to warn care providers to think very very carefully before routinely using such measures. Just what are the benefits of their use? What are the outcome measures intended to demonstrate? In order to try to convince the reader that there might be real difficulties in the interpretation of the results, the main body of the paper concentrates on the difficulties in the interpretation of data from a structured research project that has been specifically designed to evaluate an innovation in mental health care provision. The difficulties of interpreting haphazardly collected data as part of routine clinical or administrative practice will be far greater. One of the main purposes of an evaluative exercise is comparison: which approach to service provision is the better? If care providers really want to be involved in mental health service evaluation then their time would be much better spent in taking part in a large multicentre trial.

Controlled Clinical Trials as Topic↗
PubMed1994

Cognitive behavioural therapy for drug-resistant psychosis.

A small controlled trial of cognitive behaviour therapy for drug-resistant psychosis is reported. The study was designed as a pilot study for a future larger and longer randomized controlled trial. The therapy was offered to patients with a diagnosis of schizophrenia or schizo-affective psychosis who presented unremitting positive symptoms. An average of 16 sessions were delivered over a six-month period. The results of this pilot study are promising. Rates of engagement in therapy were high. The treatment group also improved significantly on a number of key symptom measures when compared with the controls. These were reductions in delusional conviction, general symptomatology and depression scores. Future studies should offer therapy over a longer period, targeting social as well as symptom change, and considering factors which will enhance maintenance of improvement.

Activities of Daily Living↗
PubMed1994

Tiapride in the prevention of relapse in recently detoxified alcoholics.

BACKGROUND: The aim was to investigate the effect of tiapride (100 mg three times a day for at least one month) on outcome following detoxification. METHOD: The setting was a tertiary referral centre. The study design was randomised, double-blind, and placebo-controlled. One hundred routinely admitted alcohol-dependent patients were entered, and 54 completed the trial. Outcome was assessed by considering drinking status at three months and six months follow-up, and by comparing psychological status at intake and follow-up using the Crown-Crisp Experiential index, the Litman Self-esteem scale and a Satisfaction with Life Situations scale. We also compared performance over the six months before admission with the three and six months of follow-up on measures of health, social and drinking variables. RESULTS: Tiapride proved better (usually at statistically highly significant levels) than placebo at promoting: abstinence, self-esteem, and satisfaction with life situations; and at reducing: alcohol consumption, use of health service resources, and levels of neuroticism. CONCLUSIONS: Tiapride merits serious consideration in the longer-term treatment of alcoholic patients.

Alcohol Drinking↗
PubMed1993

Statistics and the nature of depression.

A critical examination is made of the role that statistical methods have played in the understanding of depression. The development of instruments for measuring depression is illustrated by reference to the Beck Depression Inventory and the Hamilton Rating Scale. The controversy over the existence of one or two types of depression is examined from the perspective of the statistical tools used. Some of the problems in studies of the heritability of depression are outlined. The development of clinical trials of depression is examined, with particular reference to ECT and maintenance therapy, and the role of meta-analysis is discussed.

Data Interpretation, Statistical↗
PubMed1993

Influences upon attendance at out-patient facilities--the contribution of linear-logistic modelling.

The research on attendance at out-patient psychiatric facilities has produced conflicting evidence that provides little guidance for the practitioner. It is suggested that inadequate data exploration could explain some of the discrepant findings. Analyses of multi-way tables using linear-logistic models were undertaken to demonstrate patterns of association that cannot be revealed through the use of simple chi-square tests on two-way contingency tables. The variables chosen for these analyses were those that have produced conflicting findings in the literature on children's attendance at child guidance facilities.

Adolescent↗
PubMed1993

Shedding of virulent poliovirus revertants during immunization with oral poliovirus vaccine after prior immunization with inactivated polio vaccine.

Fecal shedding of virulent revertant polioviruses was examined in isolates from infants previously immunized with > or = 1 dose of orally administered live attenuated polio vaccine (OPV) alone, enhanced-potency inactivated polio vaccine (EIPV) alone, or a combination of both. After administration of OPV alone, vaccine poliovirus serotypes were recovered in feces within 1 week and for as long as 31-60 days in 30%-80% of subjects after 1 or 2 doses and in 30%-50% after immunization with > or = 3 doses. No revertant poliovirus shedding was observed after OPV challenge in subjects immunized previously with > or = 3 doses of OPV. However, fecal shedding of revertant poliovirus after OPV challenge was observed in 50%-100% of subjects previously immunized with > or = 3 doses of the EIPV. These findings suggest that prior immunization with EIPV does not prevent fecal shedding of revertant polioviruses after subsequent reexposure to OPV.

Feces↗
PubMed1993

Characterization and primary structure of a human immunodeficiency virus type 1 (HIV-1) neutralization domain as presented by a poliovirus type 1/HIV-1 chimera.

The poliovirus/human immunodeficiency virus (HIV) chimera S1/env/3 presents the sequence DRPEGIEEEGGERDRDRS, a known glycoprotein gp41 neutralizing domain (residues 735 to 752) of HIV IIIB in an antigenic site of the Sabin type 1 strain of poliovirus. Of 10 monoclonal antibodies raised against the sequence as presented in S1/env/3, eight were shown to neutralize HIV IIIB in vitro whereas all 10 neutralized S1/env/3, suggesting that the presentation of the sequence is comparable between HIV and the poliovirus/HIV chimera. The monoclonal antibodies were characterized by the selection of escape mutants from S1/env/3 and by Pepscan analysis. The two methods gave similar results, identifying two epitopes involving amino acids corresponding to residues 740 to 743, and to residues 745 to 750 of gp41. Mutations selected in the chimera with S1/env/3-specific MAbs are identical or similar to changes occurring in vivo in natural isolates of HIV-1. This finding suggests that the epitope may be significant in the neutralization of HIV in vivo.

Amino Acid Sequence↗
PubMed1993

Psychological testing on schoolchildren before and after pollution of drinking water in North Cornwall.

The tap water supply in Camelford, North Cornwall and environs was contaminated by aluminium and other metals in 1988. Richmond tests were routinely given before and after the pollution and here scores are compared between 39 children from schools in the contaminated area and 64 children from Cornish schools outside the polluted area. The study was retrospective and it was not possible to determine whether or how much polluted water individuals had consumed. No differences were found between groups either before or after the pollution accident nor was there any evidence for any sub-group of the polluted group which had been affected. The limits of conclusions which can be drawn from data available are discussed.

Alum Compounds↗
PubMed1993

Acting on delusions. II: The phenomenological correlates of acting on delusions.

The aim of the study was to identify the phenomenological characteristics of those delusions which are associated with action. The sample consisted of 79 patients admitted to a general psychiatric ward, each of whom described at least one delusional belief. The variables studied included the phenomenology of the delusions, and behaviour. Two behavioural ratings were used, one derived from the subjects' own description of their behaviour and the other from information provided by informants. There was no association between delusional phenomenology and acting on a delusion when the subjects' behaviour was described by informants. When action was described by the subjects themselves, acting was associated with: being aware of evidence which supported the belief and with having actively sought out such evidence; a tendency to reduce the conviction with which a belief was held when that belief was challenged; and with feeling sad, frightened or anxious as a consequence of the delusion.

Acting Out↗