Frontally mediated inhibitory processing and white matter microstructure: age and alcoholism effects

RationaleThe NOGO P3 event-related potential is a sensitive marker of alcoholism, relates to EEG oscillation in the δ and θ frequency ranges, and reflects activation of an inhibitory processing network. Degradation of white matter tracts related to age or alcoholism should negatively affect the oscillatory activity within the network.ObjectiveThis study aims to evaluate the effect of alcoholism and age on δ and θ oscillations and the relationship between these oscillations and measures of white matter microstructural integrity.MethodsData from ten long-term alcoholics to 25 nonalcoholic controls were used to derive P3 from Fz, Cz, and Pz using a visual GO/NOGO protocol. Total power and across trial phase synchrony measures were calculated for δ and θ frequencies. DTI, 1.5 T, data formed the basis of quantitative fiber tracking in the left and right cingulate bundles and the genu and splenium of the corpus callosum. Fractional anisotropy and diffusivity (λL and λT) measures were calculated from each tract.ResultsNOGO P3 amplitude and δ power at Cz were smaller in alcoholics than controls. Lower δ total power was related to higher λT in the left and right cingulate bundles. GO P3 amplitude was lower and GO P3 latency was longer with advancing age, but none of the time-frequency analysis measures displayed significant age or diagnosis effects.ConclusionsThe relation of δ total power at CZ with λT in the cingulate bundles provides correlational evidence for a functional role of fronto-parietal white matter tracts in inhibitory processing

BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

An environmental case-study of depleted uranium particulate contamination

A factory in Colonie (NY, USA) emitted c. 4.8 ± 1 tonnes of depleted uranium (DU) particulates into a suburban environment during 1958 – 1984. These particulates were initially dispersed by prevailing winds. Quadrupole inductively coupled plasma mass spectrometry (ICP-MS), laser ablation multicollector (LA-MC-) ICP-MS, scanning electron microscopy (SEM) and microfocus extended X-ray absorption fine structure (µEXAFS) spectroscopy have been used to characterise soils, dusts, vegetation, and individual particles. The concentration range of natural uranium in Colonie soils is 0.7 — 2.1 µg g-1; with total uranium up to 500 ± 40 µg g-1 in DU contaminated soils. Bioturbation can account for dispersal of contaminant from the soil surface. Primary morphologies are described for uraniferous particles from soils and dusts. Polycrystalline, often hollow microscopic uranium oxide spheres are similar to particles produced by DU munitions impacting armoured targets. These survive as UO2+x and U3O8, the least bioaccessible oxides of uranium. Fruit and wood samples were contaminated by DU, demonstrating limited bioavailability. Deviation of 235U/238U from the natural isotope ratio allows detection of DU in soils to at least 5.6 km from site. The average DU ‘end-member’ composition aggregated in soil samples comprises (2.05 ± 0.06) x10-3 235U/238U, (3.2 ± 0.1) x10-5 236U/238U, and (7.1 ± 0.3) x10 6 234U/238U. Individual uranium oxide grains were analysed by LA-MC-ICP-MS, all of which were from DU, with variable isotopic compositions (236U/238U, 235U/238U & 234U/238U). There is no evidence of enriched uranium in Colonie soils and dusts. The isotopic compositions of the Colonie particles can be explained by the inhomogeneous mixing of at least seven batches of tails from the Paducah gaseous diffusion plant, which are identified as the origins of the DU feedstocks used by National Lead Industries at Colonie. LA-MC-ICP-MS is recommended for nuclear forensic applications. This case-study is an attractive analogue for battlefield contamination

An environmental case-study of depleted uranium particulate contamination

A factory in Colonie (NY, USA) emitted c. 4.8 ± 1 tonnes of depleted uranium (DU) particulates into a suburban environment during 1958 – 1984. These particulates were initially dispersed by prevailing winds. Quadrupole inductively coupled plasma mass spectrometry (ICP-MS), laser ablation multicollector (LA-MC-) ICP-MS, scanning electron microscopy (SEM) and microfocus extended X-ray absorption fine structure (μEXAFS) spectroscopy have been used to characterise soils, dusts, vegetation, and individual particles. The concentration range of natural uranium in Colonie soils is 0.7 — 2.1 μg g-1; with total uranium up to 500 ± 40 μg g-1 in DU contaminated soils. Bioturbation can account for dispersal of contaminant from the soil surface. Primary morphologies are described for uraniferous particles from soils and dusts. Polycrystalline, often hollow microscopic uranium oxide spheres are similar to particles produced by DU munitions impacting armoured targets. These survive as UO2+x and U3O8, the least bioaccessible oxides of uranium. Fruit and wood samples were contaminated by DU, demonstrating limited bioavailability. Deviation of 235U/238U from the natural isotope ratio allows detection of DU in soils to at least 5.6 km from site. The average DU ‘end-member’ composition aggregated in soil samples comprises (2.05 ± 0.06) x10-3 235U/238U, (3.2 ± 0.1) x10-5 236U/238U, and (7.1 ± 0.3) x10-6 234U/238U. Individual uranium oxide grains were analysed by LA-MC-ICP-MS, all of which were from DU, with variable isotopic compositions (236U/238U, 235U/238U ;234U/238U). There is no evidence of enriched uranium in Colonie soils and dusts. The isotopic compositions of the Colonie particles can be explained by the inhomogeneous mixing of at least seven batches of tails from the Paducah gaseous diffusion plant, which are identified as the origins of the DU feedstocks used by National Lead Industries at Colonie. LA-MC-ICP-MS is recommended for nuclear forensic applications. This case-study is an attractive analogue for battlefield contamination.EThOS - Electronic Theses Online ServiceGBUnited Kingdo