A continuum of psychosis, one human gene, and not much else - the case for homogeneity

The contention of this paper is that psychoses are not a collection of separate and unrelated diseases, but a set of diverse expressions of a single underlying entity. It will be argued that there is a basic homogeneity of pathogenesis, that there are not multiple predisposing genes but a single gene that is associated with significant diversity. Therefore the problem is a unitary one. The challenge is to identify the nature and function of the gene. It will be argued that the gene is that by which homo sapiens has separated from other primate species, and that the diversity arises from selective pressures which continue to act on this specifically human gene

Size of hippocampal pyramidal neurons in schizophrenia

Background Meta-analyses of hippocampal size have indicated thatthis structure is smaller in schizophrenia.This could reflect a reductioninthe size of constituent neurons or a reduced number of neurons. Aims To measure the size of hippocampalpyramidalneuronsinthe hippocampalpyramidalneurons inthe brains of peoplewith andwithout schizophrenia. Method Pyramidalneuron size in hippocampal subfieldswas estimated stereologically fromsections taken at 5mmintervals throughoutthewhole length of right and left hippocampi from andleft the brains of13 peoplewith schizophrenia and16 controls.Resultswere assessed using repeated-measures analysis of covariance looking for amain effectof diagnosis and gender, andinteractions of and interactions thesewith side. Results Wewere unable to detect significantdifferences related to diagnosis, gender or side for any hippocampal subfield for this series of cases. Conclusions For this series of brains, hippocampal cell size is unchangedin schizophrenia

ProtocadherinX/Y, a Candidate Gene-Pair for Schizophrenia and Schizoaffective Disorder: A DHPLC Investigation of Gonomic Sequence

Protocadherin X and Protocadherin Y (PCDHX and PCDHY) are cell-surface adhesion molecules expressed predominantly in the brain. The PCDHX/Y gene-pair was generated by an X-Y translocation approximately 3 million years ago (MYA) that gave rise to the Homo sapiens-specific region of Xq21.3 and Yp11.2 homology. Genes within this region are expected to code for sexually dimorphic human characteristics, including, for example, cerebral asymmetry a dimension of variation that has been suggested is relevant to psychosis. We examined differences in patients with schizophrenic or schizoaffective psychosis in the genomic sequence of PCDHX and PCDHY in coding and adjacent intronic sequences using denaturing high performance liquid chromatography (DHPLC). Three coding variants were detected in PCDHX and two in PCDHY. However, neither the coding variants nor the intronic polymorphisms could be related to psychosis within families. Low sequence variation suggests selective pressure against sequence change in modern humans in contrast to the structural chromosomal and sequence changes including fixed X-Y differences that occurred in this region earlier in hominid evolution. Our findings exclude sequence variation in PCDHX/Y as relevant to the aetiology of psychosis. However, we note the unusual status of this region with respect to X-inactivation. Further investigation of the epigenetic control of PCDHX/Y in relation to psychosis is warran

Factor structure and familiality of first-rank symptoms in sibling pairs with schizophrenia and schizoaffective disorder

Background Since their introduction as diagnostic criteria by Schneider in 1937, nuclear symptoms have played a key role in concepts of schizophrenia, but their relationship to each other and to genetic predisposition has been unclear. Aims To ascertain the factor structure and familiality of nuclear symptoms. Methods Nuclear (Schneiderian) symptoms were extracted from case notes and interviews in a study of 103 sibling pairs with DSM-III-R schizophrenia or schizoaffective disorder. Results Principal components analysis demonstrated two major factors : one, accounting for about 50% of the variance, groups thought withdrawal, insertion and broadcasting, with delusions of control ; and the second, accounting for <20% of the variance, groups together third-person voices, thought echo and running commentary. Factor I was significantly correlated within sibling pairs. Conclusions The correlation within sibling pairs suggests that, contrary to the conclusion of some previous studies, some nuclear symptoms do show a degree of familiality and therefore perhaps heritability

Multiple markers of cortical morphology reveal evidence of supragranular thinning in schizophrenia.

In vivo structural neuroimaging can reliably identify changes to cortical morphology and its regional variation but cannot yet relate these changes to specific cortical layers. We propose, however, that by synthesizing principles of cortical organization, including relative contributions of different layers to sulcal and gyral thickness, regional patterns of variation in thickness of different layers across the cortical sheet and profiles of layer variation across functional hierarchies, it is possible to develop indirect morphological measures as markers of more specific cytoarchitectural changes. We developed four indirect measures sensitive to changes specifically occurring in supragranular cortical layers, and applied these to test the hypothesis that supragranular layers are disproportionately affected in schizophrenia. Our findings from the four different measures converge to indicate a predominance of supragranular thinning in schizophrenia, independent of medication and illness duration. We propose that these indirect measures offer novel ways of identifying layer-specific cortical changes, offering complementary in vivo observations to existing post-mortem studies.KW is supported by the University of Cambridge MB/PhD Programme and, together with KJW, by the Wellcome Trust. IMG by a Wellcome Trust Strategic Award (RNAG/260), and LR and PCF by the Bernard Wolfe Health Neuroscience Fund and Wellcome Trust

Risk management of biosimilars in oncology: each medicine is a work in progress

Drug licensing and drug safety monitoring for standard chemical entities have been established and are routinely used. These have resulted in a solid foundation of knowledge from which confident therapeutic decisions can be made. For many chemical entities, this advanced level of experience is also present for the generic products. The expertise surrounding the development of biosimilar competitor versions is increasing and progress is encouraging. To address the re-engineering and comparability complexities of biosimilars, the European Union imposed a requirement that risk management plans be included in the medications’ marketing applications. This paper summarizes and discusses the circumstances complicating the public’s view of drug safety, historical incidents during the transition from innovative to competitor products, as well as retrospective assessments of the development and post-marketing experiences thus far with two biosimilars. Through assessing the market entries and post-marketing experiences of biosimilars used in oncology, the healthcare field can better prepare for the next wave of comparator-products: biosimilar monoclonal antibodies

Incentive motivation in first-episode psychosis: A behavioural study

<p>Abstract</p> <p>Background:</p> <p>It has been proposed that there are abnormalities in incentive motivational processing in psychosis, possibly secondary to subcortical dopamine abnormalities, but few empirical studies have addressed this issue.</p> <p>Methods:</p> <p>We studied incentive motivation in 18 first-episode psychosis patients from the Cambridge early psychosis service CAMEO and 19 control participants using the Cued Reinforcement Reaction Time Task, which measures motivationally driven behaviour. We also gathered information on participants' attentional, executive and spatial working memory function in order to determine whether any incentive motivation deficits were secondary to generalised cognitive impairment.</p> <p>Results:</p> <p>We demonstrated the anticipated "reinforcement-related speeding" effect in controls (17 out of 19 control participants responded faster during an "odd-one-out" task in response to a cue that indicated a high likelihood of a large points reward). Only 4 out of 18 patients showed this effect and there was a significant interaction effect between reinforcement probability and diagnosis on reaction time (F_1,35= 14.2, p = 0.001). This deficit was present in spite of preserved executive and attentional function in patients, and persisted even in antipsychotic medication free patients.</p> <p>Conclusion:</p> <p>There are incentive motivation processing abnormalities in first-episode psychosis; these may be secondary to dopamine dysfunction and are not attributable to generalised cognitive impairment.</p

Body image, body dissatisfaction and weight status in south asian children: a cross-sectional study

Background Childhood obesity is a continuing problem in the UK and South Asian children represent a group that are particularly vulnerable to its health consequences. The relationship between body dissatisfaction and obesity is well documented in older children and adults, but is less clear in young children, particularly South Asians. A better understanding of this relationship in young South Asian children will inform the design and delivery of obesity intervention programmes. The aim of this study is to describe body image size perception and dissatisfaction, and their relationship to weight status in primary school aged UK South Asian children. Methods Objective measures of height and weight were undertaken on 574 predominantly South Asian children aged 5-7 (296 boys and 278 girls). BMI z-scores, and weight status (underweight, healthy weight, overweight or obese) were calculated based on the UK 1990 BMI reference charts. Figure rating scales were used to assess perceived body image size (asking children to identify their perceived body size) and dissatisfaction (difference between perceived current and ideal body size). The relationship between these and weight status were examined using multivariate analyses. Results Perceived body image size was positively associated with weight status (partial regression coefficient for overweight/obese vs. non-overweight/obese was 0.63 (95% CI 0.26-0.99) and for BMI z-score was 0.21 (95% CI 0.10-0.31), adjusted for sex, age and ethnicity). Body dissatisfaction was also associated with weight status, with overweight and obese children more likely to select thinner ideal body size than healthy weight children (adjusted partial regression coefficient for overweight/obese vs. non-overweight/obese was 1.47 (95% CI 0.99-1.96) and for BMI z-score was 0.54 (95% CI 0.40-0.67)). Conclusions Awareness of body image size and increasing body dissatisfaction with higher weight status is established at a young age in this population. This needs to be considered when designing interventions to reduce obesity in young children, in terms of both benefits and harms

Evaluation of patients on sertindole treatment after failure of other antipsychotics: A retrospective analysis

<p>Abstract</p> <p>Background</p> <p>Use of the atypical antipsychotic sertindole was suspended for four years due to safety concerns. During the suspension, the regulatory authorities required further studies, including this one, to be conducted. The purpose of this study was to determine if a subset of patients with psychotic illness exists which particularly benefits from sertindole treatment after failure of other antipsychotic drugs, including atypical antipsychotics.</p> <p>Methods</p> <p>This was a retrospective single-arm observational crossover study of 344 patients, who served as their own controls. Patients mainly from the Sertindole Safety Study who had shown good response to sertindole, and who had followed up to four alternating six month periods of treatment with sertindole and other antipsychotics, were included. (In Period 1 patients took non-sertindole treatment, in Period 2, sertindole was taken, in Period 3, patients reverted to non-sertindole treatment, and in Period 4, sertindole was taken again.) Patient records for each period of treatment were assessed for objective data: number and duration of hospitalizations due to worsening of psychotic symptoms; the amount of self-harming behaviour; indicators of social status. Retrospective evaluation of changes in clinical symptoms from the patients' records was also conducted. Dates and reasons for stopping and/or switching medication were also recorded.</p> <p>Results</p> <p>There was improvement in all objective measured parameters during the periods of sertindole treatment. In particular, the average number of hospitalizations per year due to worsening of psychotic symptoms was reduced in the following way in the group studied over four treatment periods: Period 1 (non-sertindole treatment) 3.4; Period 2 (sertindole treatment) 1.0; Period 3 (non-sertindole treatment) 2.0; Period 4 (sertindole treatment) 1.8. The duration of hospitalizations also decreased significantly during the periods of sertindole treatment. Results showed that patients improved in objective social parameters when switched to sertindole treatment; assessment of the patients' affective lives showed a significant increase in the number of patients having a stable relationship during sertindole treatment; and assessment of the number of patients employed showed an increase after the first and second switch to sertindole treatment (from Period 1 to Period 2 and from Period 3 to Period 4, respectively).</p> <p>Adverse events and lack of efficacy were the main reasons for switching to sertindole.</p> <p>Conclusion</p> <p>A group of patients benefited from sertindole after other antipsychotic treatments, including that with atypical antipsychotics, had failed. Further studies are needed to investigate if there is a specific patient profile that corresponds to these responders.</p

Ferritins: furnishing proteins with iron

Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores and examine in detail how three selected ferritins oxidise Fe2+ in order to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins