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Biomedical subjects

N Haslam

Publications and source records attributed to N Haslam.

At least 19 recordsLinked to original sources
PubMed2001

Relations between personality and depressive symptoms: a multimeasure study of dependency, autonomy, and related constructs.

Seventy-four patients seeking treatment for major depression completed four measures of dependent and autonomous personality and two measures of depressive symptomatology. Relationships among the personality measures were investigated by principal-components analysis, enabling systematic comparison of their composition. Relationships between personality components and symptom dimensions were examined to clarify specific associations that have been proposed but inconsistently obtained in previous research. Neither dependency nor autonomy were unitary constructs, and alternative measures had substantial differences in composition. Some support for symptom specificity was obtained. Dependency and autonomy have distinctive associations with depressive symptoms, but their correspondence to unitary personality dimensions and the equivalence of their alternative scales cannot be assumed.

Adult↗
PubMed2001

An investigation of the association of the prothrombin G20210A gene mutation and inflammatory bowel disease: Factor II and IBD.

BACKGROUND: A thrombotic etiology for inflammatory bowel disease (IBD) has been proposed as a result of its association with thromboembolic complications, smoking, the oral contraceptive pill, and the response of ulcerative colitis (UC) patients to heparin. We have previously demonstrated an increased prevalence of the Factor V Leiden mutation in UC and wished to investigate the frequency of the recently discovered prothrombin G20210A gene mutation in IBD. The aim of the study was to investigate the hypothesis that the prothrombic state associated with the prothrombin G20210A gene mutation is involved in the etiology of IBD. PATIENTS AND METHODS: A prospective cohort study of patients attending the Bristol Royal Infirmary and Gloucestershire Royal Hospital's IBD clinics was performed. Thirty-nine patients with IBD (24 with Crohn's disease and 15 with UC) and 100 historical controls were screened for the presence of the prothrombin gene mutation using a heteroduplex-based polymerase chain reaction technique. None of the patients with IBD had a personal history of thromboembolism, while three of them had a family history. RESULTS: No IBD patients had the prothrombin gene mutation compared with four (4%) controls (allelic frequency 2%). CONCLUSION: There does not appear to be an association of the prothrombin gene mutation with IBD and therefore it is unlikely to be involved in the etiology of IBD.

Cohort Studies↗
PubMed2000

Audit of cyclosporin use in inflammatory bowel disease: limited benefits, numerous side-effects.

BACKGROUND: The failure of standard treatments for inflammatory bowel disease (IBD) has led to the use of immuno-modulatory therapy. Most reports of the use of cyclosporin are from single specialist centres. AIM: To survey the use of cyclosporin in IBD in Bristol's three teaching hospitals. PATIENTS AND METHODS: Over a 4-year period, all patients receiving cyclosporin for IBD were identified and the following data recorded: diagnosis, duration of disease, initial treatment, date initiated, dose of cyclosporin, side-effects, initial clinical response, and current patient status. RESULTS: Thirty-three patients were identified, of whom 26 had ulcerative colitis (UC), six had Crohn's disease and one had indeterminant colitis. The most frequent indication was as 'rescue' therapy in acute severe UC. The overall initial response rate was 63%, but this was only maintained in 30% long-term patients, with over half of them reporting side-effects. Four patients had life threatening side-effects. CONCLUSION: Although the initial response rates are encouraging, the long-term results are poor and at the expense of a high incidence of side-effects. We feel that the use of cyclosporin in IBD should be reconsidered until more information from randomized controlled studies becomes available.

Adult↗
PubMed2000

Measles, month of birth, and Crohn's disease.

BACKGROUND: The rise in the incidence of Crohn's disease (CD) suggests the role of an environmental factor in the development of the disease in susceptible individuals. Perinatal exposure to infection has been proposed as such an environmental factor. AIM: To investigate the influence of birth date on the development of CD in later life. PATIENTS AND METHOD: Four registers of patients with CD, diagnosed from 1972 to 1989, were combined, and data from 1624 patients were examined. The birth dates of CD patients were compared with national birth figures for three decades (1941-50, 1951-60, and 1961-70) to avoid temporal changes in birth trends, and year of birth was compared with epidemic measles years between 1951 and 1967. Risk ratios with 95% confidence intervals (CI) and chi(2) tests were performed. RESULTS: There were marginal differences between the birth dates of the CD patients and those predicted from the general population. Further analysis of both season of birth and year halves revealed a very weak association with the first half of the year (relative risk 1.14 (95% CI 1.01-1.30)). There was no association between developing CD and birth during measles epidemics between 1951 and 1967. CONCLUSIONS: In utero or perinatal exposure to seasonal environmental factors are unlikely potential aetiological agents in the later development of CD.

Adult↗
PubMed2000

Essentialist beliefs about social categories.

This study examines beliefs about the ontological status of social categories, asking whether their members are understood to share fixed, inhering essences or natures. Forty social categories were rated on nine elements of essentialism. These elements formed two independent dimensions, representing the degrees to which categories are understood as natural kinds and as coherent entities with inhering cores ('entitativity' or reification), respectively. Reification was negatively associated with categories' evaluative status, especially among those categories understood to be natural kinds. Essentialism is not a unitary syndrome of social beliefs, and is not monolithically associated with devaluation and prejudice, but it illuminates several aspects of social categorization.

Adult↗
PubMed2000

Detecting latent taxa: Monte Carlo comparison of taxometric, mixture model, and clustering procedures.

A Monte Carlo evaluation of four procedures for detecting taxonicity was conducted using artificial data sets that were either taxonic or nontaxonic. The data sets were analyzed using two of Meehl's taxometric procedures, MAXCOV and MAMBAC, Ward's method for cluster analysis in concert with the cubic clustering criterion and a latent variable mixture modeling technique. Performance of the taxometric procedures and latent variable mixture modeling were clearly superior to that of cluster analysis in detecting taxonicity. Applied researchers are urged to select from the better procedures and to perform consistency tests.

Cluster Analysis↗
PubMed1999

An investigation of the association of the factor V Leiden mutation and inflammatory bowel disease.

BACKGROUND: A thrombotic aetiology for inflammatory bowel disease (IBD) has been proposed as a result of its association with thrombo-embolic complications, smoking, the oral contraceptive pill and the response of ulcerative colitis (UC) patients to heparin. The factor V Leiden (FVL) mutation is the commonest inherited risk factor for thrombo-embolism. AIM: The aim of the study was to investigate the hypothesis that the pro-thrombotic state associated with the FVL mutation is involved in the aetiology of IBD. PATIENTS AND METHODS: A prospective cohort study of patients attending the Bristol Royal Infirmary IBD outpatient clinic was performed. Fifty-four patients with IBD (30 with Crohn's disease (CD) and 24 with UC) and 55 historical controls were screened for the presence of FVL using the activated protein C (APC) ratio. Abnormal APC ratios were confirmed to be due to FVL using a heteroduplex-based polymerase chain reaction (PCR) technique. RESULTS: Five patients had the FVL mutation, compared to two controls. One of the patients was homozygous. Two of the patients had CD and three UC. The differences between controls and IBD patients was significant when the allelic frequency of the FVL mutation in patients with UC was compared with controls, with a risk ratio of 2.27, but with limited data. CONCLUSION: There appears to be a weak association between FVL and UC. This association is not strong enough to imply a causal relationship, but may be responsible for some of the thrombo-embolic complications.

Activated Protein C Resistance↗
PubMed1999

Predicting therapeutic outcome in severe ulcerative colitis by measuring in vitro steroid sensitivity of proliferating peripheral blood lymphocytes.

BACKGROUND: Up to 29% of patients with severe ulcerative colitis (UC) fail to respond to steroid treatment and require surgery. Previous studies have failed to show a clear correlation between failure of steroid treatment in severe UC and measures of disease severity. The reasons for treatment failure therefore remain unknown. AIM: To investigate the hypothesis that patients with severe UC who fail to respond to steroid treatment have steroid resistant T lymphocytes. METHODS: Eighteen patients with severe UC were studied. After seven days' treatment with high dose intravenous steroids they were classified as complete responders (CR), incomplete responders (IR), or treatment failures (TF). Within 48 hours of admission blood was taken and the antiproliferative effect of dexamethasone on phytohaemagglutinin stimulated peripheral blood T lymphocytes was measured. Maximum dexamethasone induced inhibition of proliferation (I(max)) was measured. RESULTS: In vitro T lymphocyte steroid sensitivity of TF and IR patients was significantly less than that of CR patients. Both TF and 3/5 IR patients had an I(max) of less than 60%; all CR patients had an I(max) of greater than 60%. No significant correlation was seen between response to treatment and disease severity on admission. When in vitro T lymphocyte steroid sensitivity was remeasured three months later, there was no difference between the groups. CONCLUSIONS: Results suggest that T lymphocyte steroid resistance is an important factor in determining response to steroid treatment in patients with severe UC and may be more predictive of outcome than disease severity.

Adult↗
PubMed1999

Detecting complex patterns in interpersonal profiles.

The assessment of interpersonal problems has advanced in recent years with the development of new methods for analysing individual profiles. These new methods assume that each profile can be modelled by a mathematical function that reflects the person's single prevailing interpersonal theme. However, some profiles may contain more complex patterns, with two or more distinct themes. Such complexities in a person's interpersonal profile might be clinically important, perhaps reflecting an interpersonal style that is conflictual. In an effort to detect complex patterns, Fourier analysis was applied to profiles of 200 psychotherapy out-patients and 200 undergraduates, using the Inventory of Interpersonal Problems. Although many profiles did not clearly manifest a single prevailing interpersonal theme, having two distinct profile peaks, their apparent complexity generally resulted from measurement error. Systematically complex or conflictual patterns were rarely detectable. Profiles of interpersonal problems may contain complex patterns, but simple patterns reflecting the prevailing interpersonal theme are apt to be more clinically informative.

Adult↗
PubMed1998

An audit of the investigation and treatment of folic acid deficiency.

On the suspicion that folate deficiency was not being thoroughly investigated we conducted a retrospective study of management in a teaching hospital. Notes from 84 consecutive patients with low red cell folates (mean age 69.5 years, range 21-95, M:F 33:51) were reviewed for haemoglobin, mean cell volume, dietary history, alcohol consumption, drug history, relevant medical history, relevant investigations, treatment, repeat measurement of red cell folate and diagnosis of deficiency. In 52 (61.9%, mean age 72.9 years, range 33-95, M:F 21:51) no diagnosis was reached. In only 32 (38.1%, mean age 63.9 years, range 21-89, M:F 12:20) was a definitive diagnosis established: 5 had coeliac disease, 1 had Crohn's disease, 9 had drug-associated deficiency (4 methotrexate, 3 phenytoin, 1 trimethoprim and 1 valproate), 1 had combined variable immunodeficiency and 16 had dietary deficiency. In most cases of folic acid deficiency no attempt was made to establish aetiology. We recommend that younger patients without an obvious cause are investigated initially by dietary assessment and measurement of anti-endomysial antibody and by duodenal biopsy with small-bowel follow-through if clinically indicated.

Adult↗
PubMed1998

Dichotomous thinking as a sign of suicide risk on the TAT.

Previous research has supported theoretical claims that dichotomous thinking may be a risk factor for suicide. However, the concept of dichotomous thinking is vague, and thus far, no measures of it have been developed. This study developed a coding scheme useful on Thematic Aperception Test (TAT; Murray, 1943) protocols and applicable to other verbal productions to refine the concept of dichotomous thinking and to assess its utility as a predictor of suicidality. Suicidal patients had a significantly elevated rate of a narrowly defined type of dichotomous thinking involving diametric or polarized possibilities. However, suicidal and nonsuicidal patients did not differ on weaker forms of dichotomous thinking involving nonexclusive or nonbinary alternatives. Suicidal patients produced shorter TAT stories than nonsuicidal patients, supporting other findings in the literature that suicidal patients tend to be cognitively and affectively "shut down." Traditionally designated "suicide cards" also yielded shorter stories but did not elicit higher rates of dichotomous thinking.

Adult↗
PubMed1997

Evidence that male sexual orientation is a matter of degree.

Whether male sexual orientation is best represented by discrete categories or by a continuum has been the focus of much debate. These alternatives were compared in an analysis of 1,138 men's scores on the Minnesota Multiphasic Personality Inventory-2 Masculinity-Femininity Scale, an established correlate of male sexual orientation. Mixtures of 2 or 3 latent distributions did not fit the observed distribution of scores better than a single normal distribution, suggesting that the latent variable underlying male sexual orientation is not discrete. Additional taxometric analyses provided convergent support for continuity. The findings were inconsistent with accounts of male sexual orientation that invoke single preponderant causes, whether genetic or environmental, and call some forms of taxonomic theorizing about sexual orientation into question.

Adult↗
PubMed1997

Is obsessive-compulsive disorder a pathology of the human disposition to perform socially meaningful rituals? Evidence of similar content.

This study investigated the theory that obsessive-compulsive disorder (OCD) is a pathology of the human disposition to perform culturally meaningful social rituals. We tested the hypothesis that the same actions and thoughts that are ego-dystonic in OCD are valued when they are appropriately performed in socially legitimated rituals. Two coders analyzed ethnographic descriptions of rituals, work, and another activity in each of 52 cultures. The coders recorded the presence or absence of 49 features of OCD and 19 features of other psychopathologies. The features of OCD were more likely to be present and occurred more frequently in rituals than in either control; rituals also contained more diverse kinds of OCD features. The features of other psychopathologies were less likely to be present and were less numerous in rituals than the features of OCD. Analysis of variance showed that OCD features discriminate between rituals and controls better than the features of other psychopathologies. These results suggest that there could be a psychological mechanism that operates normally in rituals, which can lead to OCD when it becomes hyperactivated.

Analysis of Variance↗
PubMed1997

Distinctive disorders are less prevalent.

To test the hypothesis that nosologies are biased towards recognizing highly distinctive syndromes and therefore conflate those that are less distinctive, eight subjects judged the distinctiveness of 33 DSM-IV disorders and 20 rheumatic disorders. As predicted, judged distinctiveness was negatively correlated with prevalence for both sets of disorders.

Adult↗
PubMed1996

Robustness of taxometric analysis with skewed indicators: I. A Monte Carlo study of the MAMBAC procedure.

A small Monte Carlo study was conducted to determine whether Meehl and Yonce's (1994) MAMBAC procedure--a taxometric method for testing between discrete and continuous models of latent variables--is robust when the latent variable and its manifest indicators are skewed. Analysis of constructed data sets containing three levels of skew indicated that the MAMBAC procedure is highly unlikely to yield spurious findings of discreteness ("taxonicity") even when skewness is considerable. MAMBAC appears to be a robust and promising addition to the family of taxometric procedures.

Humans↗
PubMed1996

Robustness of taxometric analysis with skewed indicators: II. A Monte Carlo study of the MAXCOV procedure.

A small Monte Carlo study was conducted to determine whether MAXCOV analysis, a taxometric method for testing between discrete ("taxonic") and continuous models of latent variables, is robust when indicators of the latent variable are skewed. Analysis of constructed data sets containing three levels of skew indicated that the MAXCOV procedure is unlikely to yield spurious findings of taxonicity even when skewness is considerable. However, care must be taken to distinguish low base-rate taxonic variables from skewed nontaxonic variables.

Humans↗
PubMed1995

The latent structure of schizotypy: I. Premorbid indicators of a taxon of individuals at risk for schizophrenia-spectrum disorders.

A taxometric analysis (R. R. Golden & P. E. Meehl, 1979) was conducted to test the hypotheses that liability for schizophrenia-spectrum disorders is dichotomously distributed and that this liability can be detected premorbidly with behavioral indicators analogous to many of the criteria for schizotypal personality disorder. Behaviors were assessed in 207 offspring of schizophrenic mothers and 104 matched offspring of normal parents in 1962, when participants' mean age was 15 years. Diagnoses on the basis of the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) were made in 1986-1989, when participants were nearly through the risk period for developing schizophrenia. The aggregation of indicators was consistent with a bimodal latent liability distribution. Membership in the schizotypal class was a sensitive and specific predictor of the emergence of schizophrenia-spectrum disorders in adulthood.

Adolescent↗