Disability in young people and adults after head injury: 12-14 year follow up of a prospective cohort

Background: There is a need to establish how long term outcome evolves after head injury (HI) and factors related to this, to inform opportunities for intervention. Objective: To determine late outcome in adults 12-14 years after hospital admission for HI and to examine relationships between injury, early and late factors and disability. Methods: A prospective cohort with HI, whose outcome was reported previously at 1 and 5-7 years after injury were followed up after 12-14 years. Participants were assessed using structured and validated measures of disability (Glasgow Outcome Scale-Extended), psychological well-being, alcohol use and health status. Results: Of 219 survivors followed-up at 5-7 years, 34 (15.5%) had died by 12-14 years. Disability remained common in survivors at 12-14 years (51%), as found at one and 5-7 years (53%). For those disabled at 1 year, outcome was dismal, with 80% dead or disabled at 12-14 years. Older age at injury, a premorbid history of brain illness or physical disability and post-injury low self-esteem and stress were associated with disability at 12-14 years. Disability changed between 5-7 and 12-14 years in 55% of survivors, improving in 23%. Late changes in disability between 5-7 and 12-14 years were associated with self-perceptions of locus of control as being 'powerful others' at 5-7 years. Conclusions: Disability is common 12-14 years after hospital admission with a head injury. For some there is a dynamic process of change in disability over time that is associated with self-perceptions of control that could be a target for intervention based research

The cerebrovascular effects of adrenaline, noradrenaline and dopamine infusions under propofol and isoflurane anaesthesia in sheep

Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsInfusions of catecholamines are frequently administered to patients receiving propofol or isoflurane anaesthesia. Interactions between these drugs may affect regional circulations, such as the brain. The aim of this animal (sheep) study was to determine the effects of ramped infusions of adrenaline, noradrenaline (10, 20, 40 µg/min) and dopamine (10, 20, 40 µg/kg/min) on cerebral blood flow (CBF), intracranial pressure (ICP), cerebrovascular resistance (CVR) and cerebral metabolic rate for oxygen (CMRO₂). These measurements were made under awake physiological conditions, and during continuous propofol (15 mg/min) or 2% isoflurane anaesthesia. All three catecholamines significantly and equivalently increased mean arterial pressure from baseline in a dose-dependent manner in the three cohorts (P0.05). Under propofol (n=6) and isoflurane (n=6), all three catecholamines significantly increased CBF (P<0.001). Dopamine caused the greatest increase in CBF, and was associated with significant increases in ICP (awake: P<0.001; propofol P<0.05; isoflurane P<0.001) and CVR (isoflurane P<0.05). No significant changes in CMRO₂ were demonstrated. Under propofol and isoflurane anaesthesia, the cerebrovascular effects of catecholamines were significantly different from the awake, physiological state, with dopamine demonstrating the most pronounced effects, particularly under propofol. Dopamine-induced hyperaemia was associated with other cerebrovascular changes. In the presence of an equivalent effect on mean arterial pressure, the exaggerated cerebrovascular effects under anaesthesia appear to be centrally mediated, possibly induced by propofol- or isoflurane-dependent changes in blood-brain barrier permeability, thereby causing a direct influence on the cerebral vasculature.http://www.aaic.net.au/Article.asp?D=200205

Calcium channel blockers for acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury is a major cause of death and disability. Calcium channel blockers (calcium antagonists) have been used in an attempt to prevent cerebral vasospasm after injury, maintain blood flow to the brain, and so prevent further damage. OBJECTIVES: To estimate the effects of calcium channel blockers in patients with acute traumatic brain injury, and in a subgroup of brain injury patients with traumatic subarachnoid haemorrhage. SEARCH STRATEGY: Handsearching and electronic searching for randomised controlled trials. SELECTION CRITERIA: Randomised controlled trials in patients with all levels of severity of clinically diagnosed acute traumatic brain injury. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the identified studies for eligibility and extracted data from each study. Summary odds ratios were calculated using the Mantel-Haenszel method. MAIN RESULTS: Six RCTs were identified as eligible for inclusion in the systematic review. The effect of calcium channel blockers on the risk of death was reported in five of the RCTs. The pooled odds ratio (OR) for the five studies was 0.91 (95% confidence interval [95%CI] 0.70-1.17). For the four RCTs that reported death and severe disability (unfavourable outcome), the pooled odds ratio was 0.85 (95%CI 0.68-1.07). In the two RCTs which reported the risk of death in a subgroup of traumatic subarachnoid haemorrhage patients, the pooled odds ratio was 0.59 (95%CI 0.37-0.94). Three RCTs reported death and severe disability as an outcome in this subgroup, and the pooled odds ratio was 0.67 (95%CI 0.46-0.98). REVIEWER'S CONCLUSIONS: This systematic review of randomised controlled trials of calcium channel blockers in acute traumatic head injury patients shows that considerable uncertainty remains over their effects. The effect of nimodipine in a subgroup of brain injury patients with subarachnoid haemorrhage shows a beneficial effect, though the increase in adverse reactions suffered by the intervention group may mean that the drug is harmful for some patients

Initiation of speciation across multiple dimensions in a rock-restricted, tropical lizard

Population isolation and concomitant genetic divergence, resulting in strong phylogeographical structure, is a core aspect of speciation initiation. If and how speciation then proceeds and ultimately completes depends on multiple factors that mediate reproductive isolation, including divergence in genomes, ecology and mating traits. Here we explored these multiple dimensions in two young (Plio-Pleistocene) species complexes of gekkonid lizards (Heteronotia) from the Kimberley–Victoria River regions of tropical Australia. Using mitochondrial DNA screening and exon capture phylogenomics, we show that the rock-restricted Heteronotia planiceps exhibits exceptional fine-scale phylogeographical structure compared to the codistributed habitat generalist Heteronotia binoei. This indicates pervasive population isolation and persistence in the rock-specialist, and thus a high rate of speciation initiation across this geographically complex region, with levels of genomic divergence spanning the “grey zone” of speciation. Proximal lineages of H. planiceps were often separated by different rock substrates, suggesting a potential role for ecological isolation; however, phylogenetic incongruence and historical introgression were inferred between one such pair. Ecomorphological divergence among lineages within both H. planiceps and H. binoei was limited, except that limestone-restricted lineages of H. planiceps tended to be larger than rock-generalists. By contrast, among-lineage divergence in the chemical composition of epidermal pore secretions (putative mating trait) exceeded ecomorphology in both complexes, but with less trait overlap among lineages in H. planiceps. This system—particularly the rock-specialist H. planiceps—highlights the role of multidimensional divergence during incipient speciation, with divergence in genomes, ecomorphology and chemical signals all at play at very fine spatial scales

Audit of head injury management in Accident and Emergency at two hospitals: implications for NICE CT guidelines

BACKGROUND: The National Institute for Clinical Excellence (NICE) has produced guidelines on the early management of head injury. This study audits the process of the management of patients with head injury presenting at Accident and Emergency (A&E) departments and examines the impact upon resources of introducing NICE guidelines for eligibility of a CT scan. METHODS: A retrospective audit of consecutive patients of any age, presenting at A&E with a complaint of head injury during one month in two northern District General Hospitals forming part of a single NHS Trust. RESULTS: 419 patients presented with a median age of 15.5 years, and 61% were male. 58% had a Glasgow Coma Score (GCS) recorded and 33 (8%) were admitted. Only four of the ten indicators for a CT scan were routinely assessed, but data were complete for only one (age), and largely absent for another (vomiting). Using just three (incomplete) indicators showed a likely 4 fold increase in the need for a CT scan. CONCLUSIONS: The majority of patients who present with a head injury to Accident and Emergency departments are discharged home. Current assessment processes and associated data collection routines do not provide the information necessary to implement NICE guidelines for CT brain scans. The development of such clinical audit systems in a busy A&E department is likely to require considerable investment in technology and/or staff. The resource implications for radiology are likely to be substantial

A New Solid Deuterium Source of Ultra-Cold Neutrons

In polarized neutron decay, the angular correlation between the neutron spin and the direction of emission of the electron is characterized by the coefficient A. Measuring A involves determining the forward-backward asymmetry of the decay beta with respect to the direction of the neutron polarization. The value of A, when combined with measurements of the neutron lifetime, determines the values of the vector and axial vector weak coupling constants, Gv and GA. The value of Gv can also be determined by measurements of superallowed nuclear beta decay and by requiring that the Cabibo-Kobayashi-Maskawi (CKM) mixing matrix be unitary along with the measured value of other elements of the CKM matrix

Parkinson disease-linked Vps35 R524W mutation impairs the endosomal association of retromer and induces α-synuclein aggregation

Endosomal sorting is a highly orchestrated cellular process. Retromer is a heterotrimeric complex that associates with endosomal membranes and facilitates the retrograde sorting of multiple receptors, including the cation-independent mannose 6-phosphate receptor for lysosomal enzymes. The cycling of retromer on and off the endosomal membrane is regulated by a network of retromer-interacting proteins. Here, we find that Parkinson disease-associated Vps35 variant, R524W, but not P316S, is a loss-of-function mutation as marked by a reduced association with this regulatory network and dysregulation of endosomal receptor sorting. Expression of Vps35 R524W-containing retromer results in the accumulation of intracellular α-synuclein-positive aggregates, a hallmark of Parkinson disease. Overall, the Vps35 R524W-containing retromer has a decreased endosomal association, which can be partially rescued by R55, a small molecule previously shown to stabilize the retromer complex, supporting the potential for future targeting of the retromer complex in the treatment of Parkinson disease

Photoproduction of Positive Mesons from Hydrogen: Results

The center-of-mass differential cross section for photoproduction of positive pions from hydrogen has been measured by the methods described in the two previous abstracts, in the angular range 40° to 150°, for photons from 220 to 475 Mev. (Photon energies refer to the Laboratory System.) Results obtained by the two methods are in essential agreement. At 90°, dσ/dω has a maximum of 2.7 X 10^(-29) cm^2/sterad near 280 Mev and falls by a factor 5 at 450 Mev. The maximum in the excitation curve is even more pronounced at larger angles, but less pronounced at smaller ones. At 40° (c.m.) the peak occurs near 350 Mev and at 450 Mev the cross section has decreased only to 0.7 the, peak value. Angular distributions in the center-of-mass system show a marked assymetry about 90°, which changes character from low energy to high. Below 325 Mev, there ii a backward maximum, whereas above 375 Mev, there is a forward maximum. The total cross section reaches a maximum near 290 Mev and decreases by about a factor 3 at 450 Mev. The results below 300 Mev agree with the data already reported from Berkeley and Cornell

Force production characteristics in Parkinson's disease

This experiment examined the preparation and the production of isometric force in Parkinson's disease (PD). PD patients, elderly, and young subjects generated force levels that were a percentage of their maximum (15, 30, 45, and 60%). Subjects were cued on the upcoming target force level and they were asked to produce the required response as fast as possible. PD patients showed a similar progression of force variability and dispersion of peak forces to that of control subjects, implying they have an accurate “internal model” of the required forces. Force production impairments were seen, however, at the within-trial level. PD patients had more irregular force-time curves that were characterized by changes in the rate of force production. The results suggest a more “noisy” output from the motor system and an inability to produce smooth forces. PD patients were also substantially slower in initiating a force production and the delay was localized in the pre-motor reaction time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46561/1/221_2004_Article_BF00253633.pd

Introduction: Dialogues about the local and the global in education

This issue of the journal is based on an OCIES-sponsored program for Early Career Researchers (ECRs). The program has established an academic alliance of ECRs to explore educational issues in Oceania and Asia through the lens of local knowledges, wisdoms and theories, helping us to de-centre ourselves from an obsession with the West and Western epistemologies. Philip Chan and Hongzhi Zhang are the conveners, and Bob Teasdale and Zane Ma Rhea have acted as mentors of the program