What kind of visual spatial attention is impaired in neglect?

The distribution of spatial attention across the horizontal meridian of the visual field, as assessed by a simple reaction time (RT) paradigm, is dramatically abnormal in neglect patients. In the contralesional hemifield, RT increases sharply from centre to periphery, while in the ipsilesional hemifield, it decreases paradoxically from centre to mid-periphery. In the present study, we firstly asked whether this abnormal distribution of spatial attention is still present when patients know in advance the location of the impending stimulus, and second whether and to which extent it may be influenced by the concomitant presence of hemianopia.

Dopamine antagonist modulation of amphetamine response as detected using pharmacological MRI.

Functional magnetic resonance imaging (fMRI), employing BOLD-contrast, was used to measure changes in regional brain activation following amphetamine administration, either alone or after pre-treatment with the dopamine D1 receptor antagonist SCH23390, or the dopamine D2 receptor antagonist, sulpiride, in anaesthetised rat. After obtaining baseline data, rats (n=8) were given amphetamine (3 g/kg i.v) and volume data sets collected for 90 mins.

MRI characterisation of a novel rat model of focal astrocyte loss.

Blood-brain barrier (BBB) integrity is lost in several neurological conditions in which astrocytes are damaged. We studied 3-chloropropanediol-induced focal lesions, a toxicant that induces early astrocytic (but not neuronal) death followed by BBB leakage. T2-weighted images illustrate regional selectivity of the lesions, affected areas including the inferior colliculi and red nuclei.

Acetaminophen availability increases in Canada with no increase in the incidence of reports of inpatient hospitalizations with acetaminophen overdose and acute liver toxicity.

In September 1999, several Canadian provinces had place-of-sale restrictions lifted that had limited the sale of acetaminophen >325 mg and packages >24 tablets (any strength) to pharmacies only. This allowed the sale of all strengths of immediate-release acetaminophen in all package sizes in nonpharmacy locations. This study's purpose was to explore the effect that lifting restrictions on acetaminophen place of sale may have had on reported hospitalizations in Canada related to acetaminophen overdose toxicity.

Vibrationally resolved K-shell photoionization of CO with circularly polarized light.

Diffraction of a low energy (<4 eV) carbon-K-photoelectron wave that is created inside a CO molecule by absorption of a circularly polarized photon is investigated. The measurements resolve the vibrational states of the K-shell ionized CO+ molecule and display the photoelectron diffraction patterns in the molecular frame. These show significant variation for the different vibrational states.

Complete photo-fragmentation of the deuterium molecule.

All properties of molecules--from binding and excitation energies to their geometry--are determined by the highly correlated initial-state wavefunction of the electrons and nuclei. Details of these correlations can be revealed by studying the break-up of these systems into their constituents. The fragmentation might be initiated by the absorption of a single photon, by collision with a charged particle or by exposure to a strong laser pulse: if the interaction causing the excitation is sufficiently understood, the fragmentation process can then be used as a tool to investigate the bound initial state.

A detrimental role for nitric oxide synthase-2 in the pathology resulting from acute cerebral injury.

Nitric oxide (NO) synthesized from the inducible isoform of nitric oxide synthase (NOS-2) has been suggested to play both beneficial and deleterious roles in various neuropathologies. To define the role of nitric oxide in traumatic brain injury, we subjected male mice lacking a functional NOS-2 gene (NOS-2-/-) and their wild-type littermates (NOS-2+/+) to mild or severe aseptic cryogenic cerebral injury. Expression of NOS-2 mRNA and protein was observed in NOS-2+/+ animals following injury.

The structure function relationship for the Prion protein.

Central to Prion diseases is the normal endogenous Prion protein, PrPC. In spite of years of research the exact function of this protein remains enigmatic. Numerous binding partners have been identified for PrPC and due to the presence of a repeated sequence of PHGGGWGQ in the proteins amino-terminus it can bind metal ions.

Fully differential cross sections for photo-double-ionization of D2.

We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double-ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis.

Children on the borderlands of autism: differential characteristics in social, imaginative, communicative and repetitive behaviour domains.

A sample of 37 children aged 4-7 years who all showed some autistic features was investigated. Children with a primary diagnosis of autism were compared with those diagnosed with a language disorder, on behaviours within four domains; social behaviour, imaginative activities, repetitive behaviour and communication. The aim was to identify potentially differentiating features of the two groups using observational ratings and questionnaire measures provided by parents and teachers.

Detection of cannabinoid agonist evoked increase in BOLD contrast in rats using functional magnetic resonance imaging.

BOLD-contrast functional magnetic resonance imaging (fMRI) was used to investigate the effects of the synthetic cannabinoid agonist HU210 on the rat brain in order to determine potential CNS sites of action for the functional effects of cannabinoids. After obtaining basal data, rats (n=8) were given the cannabinoid agonist HU210 (10 microg/kg i.v.

Focal astrocyte loss is followed by microvascular damage, with subsequent repair of the blood-brain barrier in the apparent absence of direct astrocytic contact.

Blood-brain barrier (BBB) breakdown is a feature of cerebral ischaemia, multiple sclerosis, and other neurodegenerative diseases, yet the relationship between astrocytes and the BBB integrity remains unclear. We present a simple in vivo model in which primary astrocyte loss is followed by microvascular damage, using the metabolic toxin 3-chloropropanediol (S-alpha-chlorohydrin). This model is uncomplicated by trauma, ischaemia, or primary immune involvement, permitting the study of the role of astrocytes in vascular endothelium integrity, maintenance of the BBB, and neuronal function.

Health facilitation for people with learning disabilities.

Health facilitation is a concept introduced in the white paper 'Valuing People: A New Strategy for Learning Disability for the 21st Century' (DH, 2001a). A project was set up in the West Midlands regions to look at what Primary Care Trust and specialist learning disability services were planning to do in respect of health facilitation in learning disabilities and to develop a resource tool for use by individuals working in this role. This article reiterates the extent of unmet health need experienced by people with learning disabilities and suggests that everyone involved in a caring role should be responsible for addressing their health needs.

Apolipoprotein E genotype and temperament: a longitudinal study from infancy to the late teens.

Objective: To replicate an earlier Finnish study by Keltikangas-Järvinen et al. (5) reporting that the APOE genotype is associated with temperamental traits involving increased activity.

Methods: DNA was collected from 683 Australian children who had participated in a longitudinal study of childhood temperament from 4 to 8 months up to 17 to 18 years.

Photoelectron-photoion momentum spectroscopy as a clock for chemical rearrangements: isomerization of the di-cation of acetylene to the vinylidene configuration.

We have used complete correlated momentum mapping of the photoelectron and heavy ion products from the dissociation of the di-cation of acetylene, induced by photoionizing the carbon K shell of one of the atoms, to map out the angular correlation between the electron and the axis of the target molecule. The (quasi-) symmetric decay is found to proceed through both acetylene and vinylidene configurations. By using the strongly peaked photoelectron emission to "start a clock," an upper limit of 60 fs is placed on the isomerization time from the acetylene to the vinylidene configuration.

Dancing with "death": p-methoxyamphetamine overdose and its acute management.

Para-methoxyamphetamine (PMA) is a substituted synthetic amphetamine used in the recreational drug scene. It is unusual because of the high incidence of significant morbidity and mortality in overdose. We report a case of PMA overdose in South Australia, and review our experience with the drug.

Auger electron emission from fixed-in-space CO.

We have measured the angular distribution of carbon K-Auger electrons from fixed in space, core-ionized, CO molecules in coincidence with the kinetic energy release of the C+ and O+ fragments. We find a very narrow ejection of Auger electrons in the direction of the oxygen and an oscillatory diffraction pattern. Even for similar electron energies, the angular distribution strongly depends on the symmetry of the final state.

The reach-to-grasp movement in children with autism spectrum disorder.

Autism is associated with a wide and complex array of neurobehavioural symptoms. Examination of the motor system offers a particularly appealing method for studying autism by providing information about this syndrome that is relatively immune to experimental influence. In this article, we considered the relationship between possible movement disturbance and symptoms of autism and introduced an experimental model that may be useful for rehabilitation and diagnostic purposes: the reach-to-grasp movement.

Is there an increase in the prevalence of autism spectrum disorders?

This report summarizes recent prevalence estimates for autism spectrum disorders and outlines possible reasons for an apparent increase in the numbers of children diagnosed with autism and Asperger syndrome.

The long-term significance of teacher-rated hyperactivity and reading ability in childhood: findings from two longitudinal studies.

Background: The aims of this study were twofold: first, to examine behavioural and academic outcomes of children with hyperactivity, using data from two longitudinal studies; and second, to examine comparable psychosocial outcomes for children with early reading difficulties.

Methods: Measures of teacher-rated persistent hyperactivity, and reading ability obtained during early primary school were available for children from the Australian Temperament Project and the Dunedin Multidisciplinary Health and Development Study. Both samples were followed up to assess behavioural and academic outcomes during the adolescent and early adult years.

Efficacy and safety of acetaminophen and naproxen in the treatment of tension-type headache. A randomized, double-blind, placebo-controlled trial.

The objective of this study was to evaluate and compare the efficacy and safety of single doses of acetaminophen (paracetamol) 1000 mg and naproxen 375 mg vs. placebo over a six-hour period in the treatment of tension-type headache. The treatments were compared in a randomized, double-blind, multicentre, placebo-controlled study.

The relationship between executive function abilities, adaptive behaviour, and academic achievement in children with externalising behaviour problems.

Background: Specific domains of adaptive behaviours and academic achievement may, in part, depend on executive function capacities. Executive function deficits have been found to be associated with Attention Deficit Hyperactivity Disorder (ADHD), not Oppositional Defiant Disorder/Conduct Disorder (ODD/CD).

Method: Using a sample of 110 adolescents, comprising four groups, ADHD only, co-morbid ADHD and ODD/CD, ODD/CD only, and a normal community control group, we assessed socialisation and communication skills with the Vineland Adaptive Behaviour Scales, along with reading ability, and executive functioning.