Functional Imaging Changes in the Medial Prefrontal Cortex in Adult ADHD.

OBJECTIVE: Functional imaging studies have found reduced frontal activity, mainly in dorso/ventro-lateral regions and reduced task-related de-activation of the default mode network in childhood ADHD. Adult studies are fewer and inconclusive. We aimed to investigate the potential neural bases of executive function in ADHD adults, examining brain activity during N-back task performance, and to explore the potential corrective effects of long-term methylphenidate treatment. METHOD: We recruited a large adult ADHD-combined sample and a matched control group and obtained functional magnetic resonance imaging (fMRI) images during task. ADHD participants were subdivided in a group under long-term treatment with methylphenidate (washed out for the scan) and a treatment-naive group. RESULTS: ADHD participants showed deficient de-activation of the medial prefrontal cortex during 2-back task, implying default mode network dysfunction. We found no relationship between blunted de-activation and treatment history. CONCLUSION: As de-activation failure in the medial frontal cortex is linked to lapses of attention, findings suggest a potential link to ADHD symptomatology.

Association Between Vitamin D Status and Schizophrenia: A First Psychotic Episode Study.

Vitamin D deficiency has been linked with schizophrenia. We aimed to determine whether patients with a first episode of psychosis (FEP) had lower vitamin D levels compared with controls considering their final diagnosis. We conducted a cross-sectional study determining 25-hydroxyvitamin D blood levels. 25-Hydroxyvitamin D levels were considered optimum at 20 ng/mL or greater. A group of 45 adult patients with FEP and a group of 22 healthy controls matched for age were recruited. The patient group was subdivided in two final diagnosis groups (schizophrenia versus other psychoses) after a 6-month follow-up. Average vitamin D values were deficient for FEP patients, especially those 22 with a final diagnosis of schizophrenia. These results relating vitamin D and schizophrenia generate interest to further examine this association.

Brain abnormalities in adults with Attention Deficit Hyperactivity Disorder revealed by voxel-based morphometry.

UNLABELLED: Attention Deficit Hyperactivity Disorder (ADHD) commonly affects children, although the symptoms persist into adulthood in approximately 50% of cases. Structural imaging studies in children have documented both cortical and subcortical changes in the brain. However, there have been only a few studies in adults and the results are inconclusive. METHOD: Voxel-based morphometry (VBM) was applied to 44 adults with ADHD, Combined subtype, aged 18-54 years and 44 healthy controls matched for age, sex and IQ. RESULTS: ADHD patients showed reduced gray matter (GM) volume in the right supplementary motor area (SMA). Using more lenient thresholds we also observed reductions in the subgenual anterior cingulate (ACC) and right dorsolateral prefrontal (DLPFC) cortices and increases in the basal ganglia, specifically in the left caudate nucleus and putamen. There was a positive correlation between the cumulative stimulant dose and volume in the right SMA and DLPFC clusters. CONCLUSIONS: The findings suggest that adults with ADHD show brain structural changes in regions belonging to the so-called cool executive function network. Long-term stimulant medication may act to normalize these GM alterations.

Fast inexact mapping using advanced tree exploration on backward search methods.

BACKGROUND: Short sequence mapping methods for Next Generation Sequencing consist on a combination of seeding techniques followed by local alignment based on dynamic programming approaches. Most seeding algorithms are based on backward search alignment, using the Burrows Wheeler Transform, the Ferragina and Manzini Index or Suffix Arrays. All these backward search algorithms have excellent performance, but their computational cost highly increases when allowing errors. In this paper, we discuss an inexact mapping algorithm based on pruning strategies for search tree exploration over genomic data. RESULTS: The proposed algorithm achieves a 13x speed-up over similar algorithms when allowing 6 base errors, including insertions, deletions and mismatches. This algorithm can deal with 400 bps reads with up to 9 errors in a high quality Illumina dataset. In this example, the algorithm works as a preprocessor that reduces by 55% the number of reads to be aligned. Depending on the aligner the overall execution time is reduced between 20-40%. CONCLUSIONS: Although not intended as a complete sequence mapping tool, the proposed algorithm could be used as a preprocessing step to modern sequence mappers. This step significantly reduces the number reads to be aligned, accelerating overall alignment time. Furthermore, this algorithm could be used for accelerating the seeding step of already available sequence mappers. In addition, an out-of-core index has been implemented for working with large genomes on systems without expensive memory configurations.

Fronto-limbic dysfunction in borderline personality disorder: a 18F-FDG positron emission tomography study.

INTRODUCTION: Several functional neuroimaging studies have demonstrated abnormalities in fronto-limbic pathways when comparing borderline personality disorder (BPD) patients with controls. The present study aimed to evaluate regional cerebral metabolism in euthymic BPD patients with similar measured impulsivity levels by means of 18F-FDG PET during resting state and to compare them against a control group. METHODS: The present study evaluates regional cerebral metabolism in 8 euthymic BPD patients with 18F-FDG PET during resting state as compared to 8 controls with similar socio-geographic characteristics. RESULTS: BPD patients presented a marked hypo-metabolism in frontal lobe and showed hyper-metabolism in motor cortex (paracentral lobules and post-central cortex), medial and anterior cingulus, occipital lobe, temporal pole, left superior parietal gyrus and right superior frontal gyrus. No significant differences appeared in basal ganglia or thalamus. CONCLUSIONS: Results reveal a dysfunction in patients' frontolimbic network during rest and provide further evidence for the importance of these regions in relation to BPD symptomatology.

Integrating TRENCADIS components in gLite to share DICOM medical images and structured reports.

The problem of sharing medical information among different centres has been tackled by many projects. Several of them target the specific problem of sharing DICOM images and structured reports (DICOM-SR), such as the TRENCADIS project. In this paper we propose sharing and organizing DICOM data and DICOM-SR metadata benefiting from the existent deployed Grid infrastructures compliant with gLite such as EGEE or the Spanish NGI. These infrastructures contribute with a large amount of storage resources for creating knowledge databases and also provide metadata storage resources (such as AMGA) to semantically organize reports in a tree-structure. First, in this paper, we present the extension of TRENCADIS architecture to use gLite components (LFC, AMGA, SE) on the shake of increasing interoperability. Using the metadata from DICOM-SR, and maintaining its tree structure, enables federating different but compatible diagnostic structures and simplifies the definition of complex queries. This article describes how to do this in AMGA and it shows an approach to efficiently code radiology reports to enable the multi-centre federation of data resources.

Predictors of schizophrenia in patients with a first episode of psychosis.

Early identification of schizophrenia in patients with a first episode of psychosis (FEP) may help to avoid inappropriate treatment and may enhance long-term outcome by addressing issues such as family network, treatment adherence and functional and symptomatic outcome. It was the aim of the study to determine baseline variables that significantly predicted a diagnosis of schizophrenia in patients with FEP. The sample consisted of 133 FEP patients hospitalized for at least 6 weeks, in whom a DSM-IV diagnosis was confirmed after 1 year follow-up. Patients were divided into two groups, those with a diagnosis of schizophrenia (Schizophrenia group, n=63; 47.8%), and those with other psychosis, who were grouped under Non-Schizophrenic Psychosis (NSP, n=70; 52.2%). Sociodemographic (marital status, educational level) and clinical variables were recorded for each patient. Substance use (alcohol, cannabis and cocaine) did not statistically differ between the two groups. Absence of characteristics defined as criteria for good prognosis, lack of > or = 20% improvement in the total Positive and Negative Syndrome Scale score at 6 weeks, and a poor premorbid adjustment as determined by the Premorbid Adjustment Scale score significantly predicted the presence of schizophrenia. The regression model including these three variables achieved a predictive value of 76.3%, with a sensitivity of 74.6% and a specificity of 77.9%.

Using grid-enabled distributed metadata database to index DICOM-SR.

Integrating medical data at inter-centre level implies many challenges that are being tackled from many disciplines and technologies. Medical informatics have applied an important effort on describing and standardizing Electronic Health Records, and specially standardisation has achieved an important extent on Medical Imaging. Grid technologies have been extensively used to deal with multi-domain authorisation issues and to provide single access points for accessing DICOM Medical Images, enabling the access and processing to large repositories of data. However, this approach introduces the challenge of efficiently organising data according to their relevance and interest, in which the medical report is a key factor. The present work shows an approach to efficiently code radiology reports to enable the multi-centre federation of data resources. This approach follows the tree-like structure of DICOM-SR reports in a self-organising metadata catalogue based on AMGA. This approach enables federating different but compatible distributed repositories, automatically reconfiguring the database structure, and preserving the autonomy of each centre in defining the template. Tools developed so far and some performance results are provided to prove the effectiveness of the approach.

El trastorno delirante. Revisando los aspectos de la paranoia / Delusional disorder. Revision of some aspects of paranoia

Se revisa el trastorno delirante desde su historia y concepto hasta sus posibilidades terapéuticas en la actualidad, analizando la epidemiología, clínica, aspectos diagnósticos, curso y pronóstico. Nos encontramos ante una patología poco común que se caracteriza por la presencia de ideas delirantes de instauración insidiosa, basadas en un mecanismo interpretativo y que habitualmente aparecen en una estructura de personalidad premórbida determinada. La prevalencia es de 1-4 por ciento de todos los pacientes ingresados en hospitales psiquiátricos. La media de la edad de inicio está alrededor de los 40 años y es ligeramente más frecuente en mujeres. Muchos pacientes están casados y trabajan, existiendo cierta asociación con la inmigración reciente y un estatus socioeconómico bajo. Suele haber un factor ambiental favorecedor al inicio del trastorno. Es frecuente la existencia de antecedentes familiares de trastorno psiquiátrico aunque la prevalencia de esquizofrenia y psicosis afectivas no está incrementada. El tipo de trastorno delirante más frecuente es el persecutorio. Se cree que el trastorno delirante es un diagnóstico estable, de tal forma que menos de un 25 por ciento de los pacientes evolucionan hacia la esquizofrenia y menos de un 10 por ciento evolucionan hacia los trastornos del estado de ánimo. Con un tratamiento adecuado tiene un buen pronóstico si bien la mayoría presentan dificultades de aceptación del mismo (AU)