Pasteurella multocida meningitis in infancy - (a lick may be as bad as a bite)

Pasteurella multocida is the commonest cause of local infection after an animal bite, but is an unusual cause of meningitis. We report a case of P. multocida meningitis occurring in a 7-week-old infant which was contracted after non-traumatic contact with a household pet, that is, without any animal bite or scratch. The organism may be easily confused with more common Gram-negative pathogens. In this case, it was initially incorrectly diagnosed as Haemophilus influenzae type b (Hib); a possibility which has important implications in the era of routine use of Hib vaccine in infant immunisation programs.

CONCLUSION

Pasteurella multocida is an unusual, but serious cause of meningitis in infancy. It is potentially preventable by the avoidance of contact between young infants and the saliva of household pets, in particular by assiduous hand hygiene.

Striatal preproenkephalin gene expression is upregulated in acute but not chronic parkinsonian monkeys: implications for the contribution of the indirect striatopallidal circuit to parkinsonian symptomatology

This study examined the extent of striatal dopamine (DA) denervation and coincident expression of preproenkephalin (PPE) mRNA in monkeys made parkinsonian by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration. Some animals (n = 4) became moderately parkinsonian after receiving large doses of MPTP over short periods of time and were symptomatic for only a short period of time (1-3 months; acute parkinsonian group). Other animals became moderately parkinsonian after receiving either escalating doses of MPTP over long periods (4-6 months; n = 5) or a high dose of MPTP over a short period (<1 month; n = 1) and remained symptomatic for an extended period (>8 months; chronic parkinsonian group). Despite similar symptomatology and similar degrees of striatal DA denervation at the time of their deaths, only acute parkinsonian animals had significantly increased PPE expression in sensorimotor striatal regions. PPE expression in chronic parkinsonian animals was either not changed or significantly decreased in most striatal regions. These findings suggest that the duration and not the extent of striatal DA denervation is a critical factor in modulating changes in striatal PPE expression. Furthermore, these results question the role of increased activity in the enkephalin-containing indirect striatopallidal pathway in the expression of parkinsonian symptoms.

Dichotomy between naïve and memory CD4(+) T cell responses to Fas engagement

Engagement of Fas (APO-1, CD95), a member of the tumor necrosis factor receptor superfamily, can induce apoptotic cell death. However, Fas engagement also can costimulate lymphocyte proliferation. The physiologic regulation of these two outcomes is poorly understood. Here, we have used two systems, the first in vitro and the second in vivo, to demonstrate that naïve and memory CD4(+) T cells display dichotomous responses to Fas ligation. Naïve CD4(+) T cells (CD44(lo), CD45RB+, CD62L+) die as a consequence of Fas ligation in the presence of anti-CD3 antibody, whereas memory T cells (CD44(hi), CD45RB-, CD62L-), freshly isolated from the same starting population and subjected to the same stimulation conditions, are costimulated to proliferate by Fas ligation. In vitro, we demonstrate that CD28-mediated signals or T helper 1 and T helper 2 differentiation cytokines alter the response of naïve T cells, but not of memory T cells, to Fas ligation. In vivo experiments in hen egg lysozyme (HEL) T cell receptor transgenic mice show that CD4(+) T cells from HEL-naïve mice are killed by Fas ligation, but CD4(+) T cells from long-term HEL-exposed mice are costimulated by Fas ligation. Thus, the physiological outcome of Fas ligation in CD4(+) T cells is determined primarily by the antigenic history of the T cell.

The structure of genetic and environmental risk factors for three measures of disordered eating

BACKGROUND

The study explored the genetic and environmental risk factors for both the behaviours and attitudes characteristic of disordered eating.

METHODS

In three waves of data collection, information was collected from female twins regarding their eating and attitudes towards eating, weight and shape. The first assessment consisted of a self-report questionnaire (1988-9) with 1682 women. The second assessment consisted of a semi-structured psychiatric interview schedule (1992-3), completed by 1852 women, many of whom had completed Wave 1 assessment. The third assessment, with 325 women chosen from Waves 1 and 2 (1995-6), consisted of a semi-structured interview (the Eating Disorder Examination).

RESULTS

As only one twin pair was concordant for lifetime bulimia nervosa at Wave 3 assessment, ordinal measures of all assessments were used in a multivariate genetic analysis. Results indicated that additive genetic and non-shared environmental influences best explained variance in liability to disordered eating, with about 60% (95% CI 50-68) of the variance explained by genetic factors. Comparison with a model allowing for the effects of shared environment indicated genetic factors accounted for a similar degree of variance (59%, 95% CI 36-68).

CONCLUSION

Liability to the development of the behaviours and attitudes characteristic of eating disorders is best explained by both environmental and genetic factors, with covariation between the three measures best explained by a single latent phenotype of disordered eating which has a heritability of 60%.

The role of body dissatisfaction and bingeing in the self-esteem of women with type II diabetes

This study investigated the impact of body dissatisfaction and binge eating on self-esteem in women with Type II diabetes. The relationship of body dissatisfaction and bingeing to perceived blood glucose control was also assessed. Questionnaires were completed by a total of 215 women: 125 women with Type II diabetes and 90 comparison women, who were roughly matched for age, education, and ethnicity. When actual weight (BMI) was statistically controlled, there was no difference between the groups in body dissatisfaction or bingeing behavior. The women with diabetes, however, had significantly lower self-esteem. Further, bingeing made a significant contribution to their self-esteem, in contrast to the women without diabetes. For the women with diabetes, body dissatisfaction and bingeing were also related to perceived blood glucose control, although only bingeing remained significant when both variables were entered into the regression equation. It was concluded that diabetes broadens the domains of body dissatisfaction which are related to self-esteem.

A genetic analysis of the eating and attitudes associated with bulimia nervosa: dealing with the problem of ascertainment in twin studies

Little is known about the etiology of bulimia nervosa and the attitudes associated with it. We have undertaken a study of selected (45 pairs) and unselected (106 pairs) female twins to elucidate the broad causes of individual differences in these behaviours and attitudes. The selected sample was chosen on the basis of at least one of the twin pair having a lifetime incidence of bulimia nervosa. Biometrical model fitting, which corrected for the biased twin correlations of the ascertained group, was used to investigate the genetic and environmental risk factors contributing to the development of bulimia nervosa. The best-fitting model showed that individual variation was best explained by additive genetic influences (62%) and nonshared environmental influences (38%). The proportion of genetic variance affecting individual variation in the ascertained group and the random group was not found to be significantly different. In summary, it is suggested that it may not be necessary to supplement a randomly selected sample with an ascertained sample when investigating the liability to a low-prevalence psychiatric disorder if a continuous measure of that disorder is available.

Genetic and environmental risk factors for the weight and shape concerns characteristic of bulimia nervosa

BACKGROUND

This study seeks to identify the genetic and environmental risk factors for the overvalued ideas that are characteristic of bulimia nervosa, using a biometrical model fitting approach with twin data.

METHODS

The Eating Disorder Examination (EDE), which can be used to gain continuous measures of dietary restraint, eating concern, weight concern and shape concern, was administered to 325 female twins, both monozygotic (MZ) and dizygotic (DZ). For each subscale, questions were asked concerning the month prior to interview and lifetime prevalence ('ever').

RESULTS

Model fitting indicated that there is a powerful role of the environment in shaping women's attitude towards weight, shape, eating and food, ranging from 38% to 100% of the variance. For all subscales, with the exception of weight concern, the best explanation for individual variation was one that incorporated additive genetic and non-shared environmental influences. In contrast, model fitting indicated that non-shared and shared environmental influences best explained the variance of weight concern.

CONCLUSIONS

With the exception of the Shape Concern subscale, environmental factors make a greater contribution than genetic factors to the development of the overvalued ideas that are seen to be one of the triggers for the development of bulimia nervosa. Given this substantial role of the environment influences, it seems likely that environmental manipulation can be effective in the prevention of bulimia nervosa.

Chronic neuroleptic treatment alters expression of glial glutamate transporter GLT-1 mRNA in the striatum

Recent reports have shown that typical neuroleptics may enhance glutamatergic neurotransmission and that these effects might in part underlie motor side effects of chronic neuroleptic treatment. Since glutamate reuptake is the primary mechanism for controlling extracellular glutamate levels, the present study was conducted to examine whether chronic neuroleptic exposure alters gene expression for the glutamate transporter GLT-1 in the striatum. Although both haloperidol and clozapine treatment for 30 days significantly decreased GLT-1 expression from normal, the effects of haloperidol treatment were consistently, and in the dorsal striatum, significantly greater than those of clozapine. These findings suggest that a deficiency in glutamate transport may underlie the pathogenesis of neuroleptic-induced movement disorders.

Anorexia nervosa following gastric reduction surgery for morbid obesity

Anorexia nervosa and morbid obesity are popularly considered to be opposite ends of the eating disorder spectrum. Research and clinical experience, however, suggest common psychological factors in a subgroup of obese people. This paper details case reports of two subjects who developed anorexia nervosa following gastric reduction surgery for morbid obesity. Clinical profiles, treatment, and outcome are reported. Psychological similarities between morbid obesity and anorexia nervosa in these subjects are explored. Implications for the selection of subjects for gastric reduction surgery and management after surgery are discussed.

A comparison of the Eating Disorder Examination and a general psychiatric schedule

OBJECTIVE

The aim of this study is to investigate the adequacy of a general interview schedule for the purpose of assessing bulimia nervosa.

METHOD

In two waves of data collection 18-24 months apart, 250 women were assessed for disordered eating. The first interview was typical of that included in many psychiatric interview schedules and was used to screen women for selection in a subsequent interview. This latter interview, using the Eating Disorder Examination, represents the 'gold standard' for the assessment of disordered eating.

RESULTS

While the psychiatric interview satisfactorily assessed disturbed eating in general, it seemed less capable of accurately assessing cases of bulimia nervosa in particular, the major weakness being the overestimation of binge-eating.

CONCLUSIONS

Structured psychiatric interviews are suitable for screening purposes to identify women with disordered eating, but identification of bulimia nervosa requires further assessment with a suitable instrument.

Comparison of cognitive style in bulimia nervosa and depression

This study investigated the global and specific cognitive style associated with bulimia nervosa. Three groups of women (women with bulimia nervosa, women with major depression, and controls) completed measures of eating disorder severity, depression, dysfunctional cognitions and irrational beliefs. The control group was found to report significantly lower levels of cognitive distortions and irrational beliefs overall than both women with bulimia nervosa and women with depression. However, no difference was found between the latter two groups. Furthermore, the pattern of individual cognitions and beliefs was exactly the same. When depression was statistically controlled, cognitive style no longer differentiated between the control group and two clinical groups. These results have implications for improving the effectiveness of cognitive behaviour therapy for bulimia nervosa.

Differences between treatment seekers in an obese population: medical intervention vs. dietary restriction

This study examined two groups of people who were pursuing treatment for obesity: either medical intervention (a hospital group; N = 20) or support for dietary restriction (a community group; N = 18). This study addressed four questions: (1) Were there differences between the two groups in terms of their psychological distress (as measured by the Symptom Checklist)? (2) Does binge eating moderate psychological distress? (3) Do feelings of ineffectiveness moderate psychological distress? and (4) Which variables best accounted for group membership (i.e., type of treatment sought)? Results suggested that the hospital group was significantly more distressed than the community group. However, there were no differences between the two groups with respect to binge eating or feelings of ineffectiveness. These findings suggest that it is the effects of morbid obesity that are most likely to moderate psychological distress.

Characteristics of interview refusers: women who decline to participate in interviews relating to eating

OBJECTIVES

The aim of this study was to compare the eating habits and weight ranges of 27 women who refused to participate in a semistructured interview on eating with 25 women who agreed to participate, to determine if there were any systematic differences between the two groups.

METHOD

The women had previously completed a general psychiatric interview that also included a lifetime DSM-III-R diagnosis of eating disorders. About 2 years after this interview, the women were asked to participate in an interview that would specifically examine eating behaviors.

RESULTS

In contrast to the results of previous studies, this study found that there was no difference between women who refused or agreed to participate in an interview about eating, in terms of their eating problems or weight ranges.

CONCLUSIONS

It seems that eating or weight problems need not be overrepresented in groups who refuse to participate in surveys about eating, thereby undermining the accuracy of prevalence rates in the general population. Suggestions for achieving this representation are discussed.

Interpretive bias for benign sensations in panic disorder with agoraphobia

The present study further examines the cognitive model of panic disorder by investigating two questions. The first is whether panic patients misinterpret bodily sensations which are symptoms of either nonanxious states or harmless events. The second is whether panic patients are able to provide benign subsequent explanations for bodily sensations which have initially been interpreted in an anxiety-related manner. Two groups of subjects were used, 15 panic disorder patients with agoraphobia and 15 controls, matched on verbal fluency, age and gender. Compared to controls, patients failed to identify overt explanations for bodily sensations which are due to nonanxious states or harmless events. Patients also misinterpreted bodily sensations in ambiguous scenarios by providing more anxiety-related initial interpretations than controls. Furthermore, compared to controls, patients provided significantly more anxiety-related initial interpretations which they were unable to subsequently reinterpret in a benign manner. These results provide support for the cognitive theory of panic disorder as authored by Clark and his colleagues.

The Beck Anxiety Inventory: reexamination of factor structure and psychometric properties

Several exploratory factor-analytic studies of the Beck Anxiety Inventory (BAI; Beck, Epstein, Brown, & Steer, 1988) have reported two, four, and five factors. This study evaluated the fit of four competing models to data provided by a sample of 350 undergraduates. Results of the initial confirmatory factor analyses (CFA) provided strong support for the fit of the four-factor oblique model. Next, we respecified the four-factor model as a single second-order BAI. Results showed that the second-order model also provided adequate fit to the data. Evidence also supported the psychometric indices of reliability and convergent validity. Finally, we examined the relation of the BAI to several demographic variables. Limitations of the study are discussed.

The Beck Anxiety Inventory: reexamination of factor structure and psychometric properties

Several exploratory factor-analytic studies of the Beck Anxiety Inventory (BAI; Beck, Epstein, Brown, & Steer, 1988) have reported two, four, and five factors. This study evaluated the fit of four competing models to data provided by a sample of 350 undergraduates. Results of the initial confirmatory factor analyses (CFA) provided strong support for the fit of the four-factor oblique model. Next, we respecified the four-factor model as a single second-order BAI. Results showed that the second-order model also provided adequate fit to the data. Evidence also supported the psychometric indices of reliability and convergent validity. Finally, we examined the relation of the BAI to several demographic variables. Limitations of the study are discussed.

Assessing the prevalence of eating disorders in an Australian twin population

OBJECTIVE

This paper examines the prevalence of disordered eating in a female Australian twin population aged between 28 and 90 years in 1993.

METHOD

In two waves of data collection, the eating behaviour of 3869 female twins was first assessed in 1988-1989 by self-report questionnaire and then in 1992-1993 with a telephone interview, using the Semi-Structured Assessment for the Genetics of Alcoholism interview.

RESULTS

It was found that about 0.4% of the women have a lifetime prevalence of anorexia nervosa and 1.8% of the group have suffered from bulimia nervosa. The incidence of bulimia nervosa but not anorexia nervosa was markedly higher for those women under 45 (2.3% bulimia nervosa) than for those women 45 years or older. Furthermore, one in three women have at some stage in their life used some extreme method of weight control.

CONCLUSIONS

The levels of bulimia nervosa and anorexia nervosa found are commensurate with those found in smaller studies in Australia and other parts of the world. The finding of widespread use of extreme weight control methods is of concern as this behaviour is a well-recognised precursor to more serious eating disorders.

Structure of disordered eating in a twin community sample

OBJECTIVE

To describe the types of eating problems experienced by women in an Australian twin population.

METHOD

Questions assessing preoccupation with weight or shape, use of various methods of weight control, difficulties with weight control, disordered eating, or binging, were administered to a group of 3,869 female twins. Exploratory and confirmatory factor analyses were used to summarize and describe problematic eating behaviors.

RESULTS

For those women experiencing problems with eating, five groups could be identified. These were overweight women who were dissatisfied with their weight and shape, underweight women struggling with anorexic behaviors, women who were having problems with binging, women who were using more extreme methods of weight control such as vomiting, laxatives, and starvation, and overweight women who were using slimming and fluid tablets for weight control. Confirmatory factor analysis suggested that this factor model is an acceptable fit to the data and that the factor structure generalizes well across two groups viz, the first-born and second-born twins.

DISCUSSION

It was concluded that future studies aiming to develop a general description of eating problems in the community should specifically assess the purging behaviors used by women.

Patients with bulimia nervosa who fail to engage in cognitive behavior therapy

Although cognitive behavioral treatment is the treatment of choice in bulimia nervosa, patients' response is variable. A minority of patients do not respond at all and some never engage in treatment. This paper concerns the latter group. A case series of six such patients with whom treatment could not be initiated is compared with a group who received a full course of treatment. The group with whom treatment could not begin were found to have a longer history of disorder, to report excessive laxative abuse, to have more severe depressed mood and a greater dissatisfaction with their body weight. In addition, they were more likely to have abused psychoactive substances, engaged in episodes of self-harm, and have a lower self-esteem. They were also more likely to be diagnosed as having borderline personality disorder. Patients presenting with the wide range of difficulties characteristic of this group require a more intensive form of treatment than standard outpatient cognitive behavior therapy.

Analysis of class II MHC structure in thymic nurse cells

During the course of thymocyte maturation, the processes of positive selection and tolerance induction are mediated by interactions between thymocyte T-cell receptors and MHC molecules on thymic stromal cells. The means by which these seemingly contrary processes can be mediated by interactions between the same molecules has long been a source of controversy. One idea which has been put forward is that the MHC molecules in different microenvironments of the thymus are not the same. We have tested this hypothesis by examining class II transcripts derived from thymic cortical epithelial cells known as thymic nurse cells, reasoning that alternative splicing of primary transcripts might give rise to a positively selecting MHC molecule. However, we found no evidence for alternative splicing of these transcripts. These results are presented and discussed with regard to implications for possible mechanisms of positive selection.

Residues of the variable region of the T-cell-receptor beta-chain that interact with S. aureus toxin superantigens

The alpha beta T-cell antigen receptor (TCR) recognizes antigenic peptides in the context of self major histocompatibility complex (MHC) molecules. The specificity of recognition of MHC plus antigen is generally determined by a combination of the variable elements of alpha- and beta-chains of the TCR. Several types of antigen, however, have been identified that, when bound to MHC molecules, stimulate T cells bearing particular variable-region beta-chain (V beta) elements irrespective of the other variable components of the TCR. These have been termed 'superantigens', and here we are concerned with one type of superantigen, the toxins produced by Staphylococcus aureus. T cells have been found that bear closely related members of the same V beta family but respond differently to S. aureus toxins; in particular, cells bearing the human V beta 13.2 element respond to toxin SEC2, whereas cells bearing human V beta 13.1 do not. We have now defined the residues of the V beta element responsible for this difference, and find that they reside in a region thought to lie on the side of the TCR molecule, away from the conventional antigen/MHC-binding site. The evolutionary conservation of this site may be due to its having an important role in some function of the TCR other than the binding of conventional antigen plus MHC.

Identification of the region of T cell receptor beta chain that interacts with the self-superantigen MIs-1a

Superantigen-MHC complexes are known to stimulate T cells primarily via the V beta element of the T cell receptor. In this paper we identify a number of amino acid residues that define the region of a particular V beta element interacting with one of the self-superantigens, MIs-1a. These residues are predicted to lie on a beta-pleated sheet of the T cell receptor, away from the complementarity determining regions of the receptor, which are thought to interact with complexes of conventional peptide antigens and MHC. In support of this prediction, mutations affecting MIs-1a activity have no effect on the response to conventional antigen and MHC.

Molecular basis for the nonexpression of V beta 17 in some strains of mice

The TCR alpha/beta variable element V beta 17a is expressed in all strains of mice carrying the V beta a complex in which about half of the V beta elements have been lost due to a large deletion. The mAb KJ23a detects V beta 17a containing alpha/beta receptors in these mice. Mouse strains with the V beta b complex carry a full complement of V beta genes including a structural gene for V beta 17 (V beta 17b), but no T cells reactive with KJ23a are present in these mice. Among random peripheral T cell hybridomas prepared from V beta b mice, occasional V beta 17b transcripts are found. The sequence of one of these transcripts reveals a single base difference from V beta 17a which results in a termination codon within the coding region inactivating the gene.