RIPK3 promotes islet amyloid-induced ß-cell loss and glucose intolerance in a humanized mouse model of type 2 diabetes.

OBJECTIVE: Aggregation of human islet amyloid polypeptide (hIAPP), a ß-cell secretory product, leads to islet amyloid deposition, islet inflammation and ß-cell loss in type 2 diabetes (T2D), but the mechanisms that underlie this process are incompletely understood. Receptor interacting protein kinase 3 (RIPK3) is a pro-death signaling molecule that has recently been implicated in amyloid-associated brain pathology and ß-cell cytotoxicity. Here, we evaluated the role of RIPK3 in amyloid-induced ß-cell loss using a humanized mouse model of T2D that expresses hIAPP and is prone to islet amyloid formation. METHODS: We quantified amyloid deposition, cell death and caspase 3/7 activity in islets isolated from WT, Ripk3-/-, hIAPP and hIAPP; Ripk3-/- mice in real time, and evaluated hIAPP-stimulated inflammation in WT and Ripk3-/- bone marrow derived macrophages (BMDMs) in vitro. We also characterized the role of RIPK3 in glucose stimulated insulin secretion (GSIS) in vitro and in vivo. Finally, we examined the role of RIPK3 in high fat diet (HFD)-induced islet amyloid deposition, ß-cell loss and glucose homeostasis in vivo. RESULTS: We found that amyloid-prone hIAPP mouse islets exhibited increased cell death and caspase 3/7 activity compared to amyloid-free WT islets in vitro, and this was associated with increased RIPK3 expression. hIAPP; Ripk3-/- islets were protected from amyloid-induced cell death compared to hIAPP islets in vitro, although amyloid deposition and caspase 3/7 activity were not different between genotypes. We observed that macrophages are a source of Ripk3 expression in isolated islets, and that Ripk3-/- BMDMs were protected from hIAPP-stimulated inflammatory gene expression (Tnf, Il1b, Nos2). Following 52 weeks of HFD feeding, islet amyloid-prone hIAPP mice exhibited impaired glucose tolerance and decreased ß-cell area compared to WT mice in vivo, whereas hIAPP; Ripk3-/- mice were protected from these impairments. CONCLUSIONS: In conclusion, loss of RIPK3 protects from amyloid-induced inflammation and islet cell death in vitro and amyloid-induced ß-cell loss and glucose intolerance in vivo. We propose that therapies targeting RIPK3 may reduce islet inflammation and ß-cell loss and improve glucose homeostasis in the pathogenesis of T2D.

The relationship between long-term blood pressure variability and cortical thickness in older adults.

High blood pressure variability (BPV) is a risk factor for cognitive decline and dementia, but its association with cortical thickness is not well understood. Here we use a topographical approach, to assess links between long-term BPV and cortical thickness in 478 (54% men at baseline) community dwelling older adults (70-88 years) from the ASPirin in Reducing Events in the Elderly NEURO sub-study. BPV was measured as average real variability, based on annual visits across three years. Higher diastolic BPV was significantly associated with reduced cortical thickness in multiple areas, including temporal (banks of the superior temporal sulcus), parietal (supramarginal gyrus, post-central gyrus), and posterior frontal areas (pre-central gyrus, caudal middle frontal gyrus), while controlling for mean BP. Higher diastolic BPV was associated with faster progression of cortical thinning across the three years. Diastolic BPV is an important predictor of cortical thickness, and trajectory of cortical thickness, independent of mean blood pressure. This finding suggests an important biological link in the relationship between BPV and cognitive decline in older age.

Test-retest reliability of subjective supra-threshold scaling of multiple pressure-pain sensations among healthy individuals: a study using hydraulic pressure algometry.

BACKGROUND: Supra-threshold scaling of multiple pressure-pain sensations involves delivery of varied stimulus intensities, either via stimulus-dependent or response-dependent manner, and recording of subjective pain ratings by participants. The focus of this study was to determine the intra- and inter-session reliability of pain intensity and pain unpleasantness ratings related to pressure-pain thresholds (PPTs) of just noticeable pain (JNP), weak pain (WP) and moderate pain (MP) among healthy individuals. METHODS: Fourteen healthy participants (eight women, six men) participated in three sessions of testing at varied intervals over the course of 72 h. In session one, a multiple random staircase method using hydraulic pressure algometry was used to measure PPT of JNP, WP and MP on thumbnail bed. In session 2, ratings of pain intensity and pain unpleasantness were recorded when stimuli at levels corresponding to PPT of JNP, WP and MP were repeatedly applied before and after 20 min of no intervention. RESULTS: Interclass correlation coefficient (ICC) values for pain ratings of JNP, WP and MP in intra-session reliability were 0.810, 0.826 and 0.881, respectively, whereas the values were 0.817, 0.792 and 0.910, respectively, for inter-session reliability. ICC values for pain unpleasantness were also highly consistent and repeatable. Temporal summation of pain intensity and pain unpleasantness were not related to the repeated application of pressure stimuli. CONCLUSIONS: The findings indicate that the pain intensity and pain unpleasantness ratings for stimuli at levels equal to the thresholds of JNP, WP and MP have good intra- and inter-session reliability. SIGNIFICANCE: This study showed that both pain intensity and pain unpleasantness of JNP, WP and MP have good intra- and inter-session reliability and agreement. Furthermore, the temporal summation of pain or unpleasantness is not related to repeated application of pressure stimuli. ABBREVIATIONS: JNP: Just noticeable pain; WP: Weak pain; MP: Moderate pain; PPTs: pressure-pain thresholds; HPA: Hydraulic pressure algometry; MRSM: multiple random staircase method.

Diminished motor imagery capability in adults with motor impairment: An fMRI mental rotation study.

Recent research has demonstrated that adults with probable Developmental Coordination Disorder (pDCD) show similar behavioural deficits as those observed in children DCD when performing a motor imagery task. The aim of this study was to investigate whether the pattern of neural activation in adults with pDCD during motor imagery differed from adults without motor skill impairment. Twelve adults with pDCD (5 male; age M=24.5 yrs) and 11 adults without pDCD (6 male; age M=26.7 yrs) participated. The hand rotation task was used to assess motor imagery ability, while functional neural images were acquired using a 3T MR scanner. Performance on the hand task in both groups conformed to the biomechanical constraints of real movement, supporting the use of motor imagery to complete the task. Comparisons of response time and accuracy data showed no significant group differences. Comparison of the BOLD signal activation maps identified a significant parametric difference between groups. The% BOLD signal change for increasing angle of rotation showed greater activation in controls compared to the pDCD group in the occipito-parietal and parieto-frontal networks including the middle frontal gyrus bilaterally, the left superior parietal lobe as well as in the cerebellum (lobule VI). The pattern of reduced activation in adults with pDCD is consistent with recent studies of childhood DCD that suggest atypical activation in frontal, parietal and cerebellar areas, and supports the theory that this type of impairment may be associated with disruption of parieto-frontal and parieto-cerebellar networks.

Phase I study of temozolomide in combination with thiotepa and carboplatin with autologous hematopoietic cell rescue in patients with malignant brain tumors with minimal residual disease.

Recurrence of malignant brain tumors results in a poor prognosis with limited treatment options. High-dose chemotherapy with autologous hematopoietic cell rescue (AHCR) has been used in patients with recurrent malignant brain tumors and has shown improved outcomes compared with standard chemotherapy. Temozolomide is standard therapy for glioblastoma and has also shown activity in patients with medulloblastoma/primitive neuro-ectodermal tumor (PNET), particularly those with recurrent disease. Temozolomide was administered twice daily on days -10 to -6, followed by thiotepa 300 mg/m(2) per day and carboplatin dosed using the Calvert formula or body surface area on days -5 to -3, with AHCR day 0. Twenty-seven patients aged 3-46 years were enrolled. Diagnoses included high-grade glioma (n=12); medulloblastoma/PNET (n=9); central nervous system (CNS) germ cell tumor (n=4); ependymoma (n=1) and spinal cord PNET (n=1). Temozolomide doses ranged from 100 mg/m(2) per day to 400 mg/m(2) per day. There were no toxic deaths. Prolonged survival was noted in several patients including those with recurrent high-grade glioma, medulloblastoma and CNS germ cell tumor. Increased doses of temozolomide are feasible with AHCR. A phase II study using temozolomide, carboplatin and thiotepa with AHCR for children with recurrent malignant brain tumors is being conducted through the Pediatric Blood and Marrow Transplant Consortium.

Biomedical journals lack a consistent method to detect outcome reporting bias: a cross-sectional analysis.

WHAT IS KNOWN AND OBJECTIVE: An increasing amount of recently published literature has implicated outcome reporting bias (ORB) as a major contributor to skewing data in both randomized controlled trials and systematic reviews; however, little is known about the current methods in place to detect ORB. This study aims to gain insight into the detection and management of ORB by biomedical journals. METHODS: This was a cross-sectional analysis involving standardized questions via email or telephone with the top 30 biomedical journals (2012) ranked by impact factor. The Cochrane Database of Systematic Reviews was excluded leaving 29 journals in the sample. RESULTS: Of 29 journals, 24 (83%) responded to our initial inquiry of which 14 (58%) answered our questions and 10 (42%) declined participation. Five (36%) of the responding journals indicated they had a specific method to detect ORB, whereas 9 (64%) did not have a specific method in place. The prevalence of ORB in the review process seemed to differ with 4 (29%) journals indicating ORB was found commonly, whereas 7 (50%) indicated ORB was uncommon or never detected by their journal previously. The majority (n = 10/14, 72%) of journals were unwilling to report or make discrepancies found in manuscripts available to the public. Although the minority, there were some journals (n = 4/14, 29%) which described thorough methods to detect ORB. WHAT IS NEW AND CONCLUSION: Many journals seemed to lack a method with which to detect ORB and its estimated prevalence was much lower than that reported in literature suggesting inadequate detection. There exists a potential for overestimation of treatment effects of interventions and unclear risks. Fortunately, there are journals within this sample which appear to utilize comprehensive methods for detection of ORB, but overall, the data suggest improvements at the biomedical journal level for detecting and minimizing the effect of this bias are needed.

Trauma care in Scotland: effect of rurality on ambulance travel times and level of destination healthcare facility.

AIM: The aim of this study was to determine the effect of rurality on the level of destination healthcare facility and ambulance response times for trauma patients in Scotland. METHODS: We used a retrospective analysis of pre-hospital data routinely collected by the Scottish Ambulance Service from 2009-2010. Incident locations were categorised by rurality, using the Scottish urban/rural classification. The level of destination healthcare facility was coded as either a teaching hospital, large general hospital, general hospital, or other type of facility. RESULTS: A total of 64,377 incidents met the inclusion criteria. The majority of incidents occurred in urban areas, which mostly resulted in admission to teaching hospitals. Incidents from other areas resulted in admission to a lower-level facility. The majority of incidents originating in very remote small towns and very remote rural areas were treated in a general hospital. Median call-out times and travel times increased with the degree of rurality, although with some exceptions. CONCLUSIONS: Trauma is relatively rare in rural areas, but patients injured in remote locations are doubly disadvantaged by prolonged pre-hospital times and admission to a hospital that may not be adequately equipped to deal with their injuries. These problems may be overcome by the regionalisation of trauma care, and enhanced retrieval capability.

Automated differentiation of pre-diagnosis Huntington's disease from healthy control individuals based on quadratic discriminant analysis of the basal ganglia: the IMAGE-HD study.

We investigated two measures of neural integrity, T1-weighted volumetric measures and diffusion tensor imaging (DTI), and explored their combined potential to differentiate pre-diagnosis Huntington's disease (pre-HD) individuals from healthy controls. We applied quadratic discriminant analysis (QDA) to discriminate pre-HD individuals from controls and we utilised feature selection and dimension reduction to increase the robustness of the discrimination method. Thirty six symptomatic HD (symp-HD), 35 pre-HD, and 36 control individuals participated as part of the IMAGE-HD study and underwent T1-weighted MRI, and DTI using a Siemens 3 Tesla scanner. Volume and DTI measures [mean diffusivity (MD) and fractional anisotropy (FA)] were calculated for each group within five regions of interest (ROI; caudate, putamen, pallidum, accumbens and thalamus). QDA was then performed in a stepwise manner to differentiate pre-HD individuals from controls, based initially on unimodal analysis of motor or neurocognitive measures, or on volume, MD or FA measures from within the caudate, pallidum and putamen. We then tested for potential improvements to this model, by examining multi-modal MRI classifications (volume, FA and MD), and also included motor and neurocognitive measures, and additional brain regions (i.e., accumbens and thalamus). Volume, MD and FA differed across the three groups, with pre-HD characterised by significant volumetric reductions and increased FA within caudate, putamen and pallidum, relative to controls. The QDA results demonstrated that the differentiation of pre-HD from controls was highly accurate when both volumetric and diffusion data sets from basal ganglia (BG) regions were used. The highest discriminative accuracy however was achieved in a multi-modality approach and when including all available measures: motor and neurocognitive scores and multi-modal MRI measures from the BG, accumbens and thalamus. Our QDA findings provide evidence that combined multi-modal imaging measures can accurately classify individuals up to 15 years prior to onset when therapeutic intervention is likely to have maximal effects in slowing the trajectory of disease development.

Manganese-enhanced MRI reflects seizure outcome in a model for mesial temporal lobe epilepsy.

The neurobiological processes resulting in epilepsy, known as epileptogenesis, are incompletely understood. Manganese-enhanced MRI (MEMRI) can potentially aide in this quest as it provides superior tissue contrast, particularly of the hippocampal subregions. This longitudinal study aims to characterise the changes in the hippocampus of the post kainic acid-induced status epilepticus (KASE) rat model of mesial temporal lobe epilepsy using MEMRI in vivo. Serial acquisition of T(1)-weighted MEMRI images were taken before, 2 days and 6 weeks after KASE (10-30 mg/kg, i.p.) in 14 rats and in 11 control rats, while a second cohort of control (N=6) and epileptic animals (N=10) was imaged at 2 months post KASE only. MnCl(2) (50 mM, 10 µl) was administered in the right lateral ventricle 1 day before scanning. Regions of interest were drawn around the hippocampus and several subregions of the hippocampus (CA1, CA3 and dentate gyrus). Markers of epilepsy such as spontaneous recurrent seizures, hippocampal neuronal loss and mossy fiber sprouting were quantified. A persistent increase in MEMRI signal intensity was found in the hippocampus, CA1 and dentate gyrus in the KASE group compared to the control group (ANOVA P<0.05). The intensity signal in the hippocampus and subregions correlated inversely with the frequency of spontaneous recurrent seizures in the chronic epileptic phase, however there was no relationship observed between histopathological changes such as cell loss and mossy fiber sprouting with seizures. This study demonstrates that MEMRI is able to detect imaging changes in the hippocampus during the course of epileptogenesis relevant for seizure expression. These data strongly indicate a relationship between manganese enhancement and spontaneous seizure outcome, suggesting that MEMRI could provide a preclinical biomarker for the severity of epileptogenesis in vivo in animal models.

Prefrontal activity in Huntington's disease reflects cognitive and neuropsychiatric disturbances: the IMAGE-HD study.

Functional integrity of prefrontal cortico-striatal circuits underlying executive functioning may be compromised by basal ganglia degeneration during Huntington's disease (HD). This study investigated challenged inhibitory attentional control with a shifting response-set (SRS) task whilst assessing neural response via functional magnetic resonance imaging (fMRI) in 35 healthy controls, 35 matched pre-symptomatic (pre-HD) and 30 symptomatic (symp-HD) participants. A ≥70% performance accuracy threshold allowed confident identification of neural activity associated with SRS performance in a sub-set of 33 healthy controls, 32 pre-HD and 20 symp-HD participants. SRS activated dorsolateral prefrontal and dorsal anterior cingulate cortices, premotor, parietal, and basal ganglia regions and deactivated subgenual anterior cingulate cortex. Symp-HD participants showed greater prefrontal functional responses relative to controls and pre-HD, including larger activations and larger deactivations in response to cognitive challenge, consistent with compensatory neural recruitment. We then investigated associations between prefrontal BOLD responses, SRS performance accuracy and neuropsychiatric disturbance in all participants, including those below SRS performance accuracy threshold. We observed that reduced prefrontal responsivity in symp-HD was associated with reduced accuracy in SRS performance, and with increased neuropsychiatric disturbance within domains including executive dysfunction, pathological impulses, disinhibition, and depression. These findings demonstrate prefrontal response during inhibitory attentional control usefully characterises cognitive and neuropsychiatric status in symp-HD. The functional integrity of compensatory prefrontal responses may provide a useful marker for treatments which aim to sustain cognitive function and delay executive and neuropsychiatric disturbance.

Experience with the European quality assurance guidelines for digital mammography systems in a national screening programme.

The transition to a fully digital breast screening programme, utilising three different full-field digital mammography (FFDM) systems has presented many challenges to the implementation of the European guidelines for physico-technical quality assurance (QA) testing. An analysis of the QA results collected from the FFDM systems in the screening programme over a 2-y period indicates that the three different systems have similar QA performances. Generally, the same tests were failed by all systems and failure rates were low. The findings provide some assurance that the QA guidelines are being correctly implemented. They also suggest that there is more scope for the development of the relevance of the guidelines with respect to modern FFDM systems. This study has also shown that a summary review of the QA data can be achieved by simple organisation of the QA data storage and by automation of data query and retrieval using commonly available software.

Rural and urban distribution of trauma incidents in Scotland.

BACKGROUND: Trauma systems reduce mortality and improve functional outcomes from injury. Regional trauma networks have been established in several European regions to address longstanding deficiencies in trauma care. A perception of the geography and population distribution as challenging has delayed the introduction of a trauma system in Scotland. The characteristics of trauma incidents attended by the Scottish Ambulance Service were analysed, to gain a better understanding of the geospatial characteristics of trauma in Scotland. METHODS: Data on trauma incidents collected by the Scottish Ambulance Service between November 2008 and October 2010 were obtained. Incident location was analysed by health board region, rurality and social deprivation. The results are presented as number of patients, average annual incidence rates and relative risks. RESULTS: Of the 141,668 incidents identified, 72·1 per cent occurred in urban regions. The risk of being involved in an incident was similar across the most populous regions, and decreased slightly with increasing rurality. Social deprivation was associated with greater numbers and risk. A total of 53·1 per cent of patients were taken to a large general hospital, and 38·6 per cent to a teaching hospital; the distribution was similar for the subset of incidents involving patients with physiological derangements. CONCLUSION: The majority of trauma incidents in Scotland occur in urban and deprived areas. A regionalized system of trauma care appears plausible, although the precise configuration of such a system requires further study.

Diffusion tensor imaging of acute inflammatory lesion evolution in multiple sclerosis.

The initiating events in multiple sclerosis (MS) plaque formation are poorly understood. Retrospective analysis of serial imaging data can improve the understanding of tissue changes characterising acute MS lesion evolution. This study aimed to assess lesion evolution using diffusion tensor imaging data from serially acquired scans from 22 patients with MS. Mean diffusivity (MD) and fractional anisotropy (FA) were measured from 13 suitable plaques from five patients and carefully matched regions of contralateral normal-appearing white matter. Measurement times were on average: 5 months and 1 month prior to, during, and 1 month and 2 months post gadolinium-enhancement. A significant increase in MD (7.25%) but no change in FA was observed in white matter areas that exhibited enhancement 5 months later. The pre-lesional MD increase was significantly correlated with the MD increase 2 months subsequent to enhancement (R=0.73, p=0.04) but not to the MD increase during enhancement (R=0.11). These results suggest that MD is sensitive to tissue changes that precede blood-brain barrier (BBB) breakdown by at least 5 months and that MD assessments may predict injury following BBB restoration.

A functional MRI study of motor dysfunction in Friedreich's ataxia.

Friedreich's ataxia (FRDA) is the most common form of hereditary ataxia. In addition to proximal spinal cord and brain stem atrophy, mild to moderate atrophy of the cerebellum has been reported in advanced FRDA. The aim of this study was to examine dysfunction in motor-related areas involved in the execution of finger tapping tasks in individuals with FRDA, and to investigate functional re-organization of cortico-cerebellar, cortico-striatal and parieto-frontal loops as a result of the cerebellar pathology. Thirteen right-handed individuals with FRDA and fourteen right-handed controls participated. Functional MRI images were acquired during four different finger tapping tasks consisting of visually cued regular and irregular single finger tapping tasks, a self-paced regular finger tapping task, and a visually cued multi-finger tapping task. Both groups showed significant activation of the motor-related network including the pre-central cortex and supplementary motor area bilaterally; the left primary motor cortex, somatosensory cortex and putamen; and the right cerebellum. During the visually cued regular finger tapping task, the right hemisphere of the cerebellar cortex, bilateral supplementary motor areas and right inferior parietal cortex showed higher activation in the healthy control group, while in individuals with FRDA the left premotor cortex, left somatosensory cortex and left inferior parietal cortex were more active. In addition, during the visually cued irregular finger tapping task, the right middle temporal gyrus in the control group and the right superior parietal lobule and left superior and middle temporal gyri in the individuals with FRDA showed higher activation. During visually cued multi-finger tapping task, the control group showed higher activation in the bilateral middle frontal gyri, bilateral somatosensory cortices, bilateral inferior parietal lobules, left premotor cortex, left supplementary area, right superior frontal gyrus and right cerebellum, while individuals with FRDA showed increased activity in the left inferior parietal lobule, left primary motor cortex, left middle occipital gyrus, right somatosensory cortex and the left cerebellum. Only the right crus I/II of the cerebellum showed higher activation in individuals with FRDA during the self-paced regular finger tapping task, whereas wide-spread regions including the left superior frontal gyrus, left central opercular cortex, left somatosensory cortex, left putamen, right cerebellum, bilateral primary motor cortices, bilateral inferior parietal lobules and the left insula were more active in the control group. Although the pattern of the BOLD signal from the putamen was different during the self-paced regular finger tapping task to the other tasks in controls, in individuals with FRDA there was no distinction of the signal between the tasks suggesting that primary cerebellar pathology may cause secondary basal ganglia dysregulation. While individuals with FRDA tapped at a slightly lower rate (0.59Hz) compared with controls (0.74Hz) they showed significantly decreased activity of the SMA and the inferior parietal lobule, which may suggest disruption to the fronto-parietal connections. These findings suggest that the motor impairments in individuals with FRDA result from dysfunction extending beyond the spinal cord and cerebellum to include sub-cortical and cortical brain regions.

Decreased functional brain activation in Friedreich ataxia using the Simon effect task.

The present study applied the Simon effect task to examine the pattern of functional brain reorganization in individuals with Friedreich ataxia (FRDA), using functional magnetic resonance imaging (fMRI). Thirteen individuals with FRDA and 14 age and sex matched controls participated, and were required to respond to either congruent or incongruent arrow stimuli, presented either to the left or right of a screen, via laterally-located button press responses. Although the Simon effect (incongruent minus congruent stimuli) showed common regions of activation in both groups, including the superior and middle prefrontal cortices, insulae, superior and inferior parietal lobules (LPs, LPi), occipital cortex and cerebellum, there was reduced functional activation across a range of brain regions (cortical, subcortical and cerebellar) in individuals with FRDA. The greater Simon effect behaviourally in individuals with FRDA, compared with controls, together with concomitant reductions in functional brain activation and reduced functional connectivity between cortical and sub-cortical regions, implies a likely disruption of cortico-cerebellar loops and ineffective engagement of cognitive/attention regions required for response suppression.

A randomized trial of high-dose vitamin D2 in relapsing-remitting multiple sclerosis.

OBJECTIVE: Higher latitude, lower ultraviolet exposure, and lower serum 25-hydroxyvitamin D (25OHD) correlate with higher multiple sclerosis (MS) prevalence, relapse rate, and mortality. We therefore evaluated the effects of high-dose vitamin D2 (D2) in MS. METHODS: Adults with clinically active relapsing-remitting MS (RRMS) were randomized to 6 months' double-blind placebo-controlled high-dose vitamin D2, 6,000 IU capsules, dose adjusted empirically aiming for a serum 25OHD 130-175 nM. All received daily low-dose (1,000 IU) D2 to prevent deficiency. Brain MRIs were performed at baseline, 4, 5, and 6 months. Primary endpoints were the cumulative number of new gadolinium-enhancing lesions and change in the total volume of T2 lesions. Secondary endpoints were Expanded Disability Status Scale (EDSS) score and relapses. RESULTS: Twenty-three people were randomized, of whom 19 were on established interferon or glatiramer acetate (Copaxone) treatment. Median 25OHD rose from 54 to 69 nM (low-dose D2) vs 59 to 120 nM (high-dose D2) (p = 0.002). No significant treatment differences were detected in the primary MRI endpoints. Exit EDSS, after adjustment for entry EDSS, was higher following high-dose D2 than following low-dose D2 (p = 0.05). There were 4 relapses with high-dose D2 vs none with low-dose D2 (p = 0.04). CONCLUSION: We did not find a therapeutic advantage in RRMS for high-dose D2 over low-dose D2 supplementation. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that high-dose vitamin D2 (targeting 25OHD 130-175 nM), compared to low-dose supplementation (1,000 IU/d), was not effective in reducing MRI lesions in patients with RRMS.

Cortical activation and lamina terminalis functional connectivity during thirst and drinking in humans.

The pattern of regional brain activation in humans during thirst associated with dehydration, increased blood osmolality, and decreased blood volume is not known. Furthermore, there is little information available about associations between activation in osmoreceptive brain regions such as the organum vasculosum of the lamina terminalis and the brain regions implicated in thirst and its satiation in humans. With the objective of investigating the neuroanatomical correlates of dehydration and activation in the ventral lamina terminalis, this study involved exercise-induced sweating in 15 people and measures of regional cerebral blood flow (rCBF) using a functional magnetic resonance imaging technique called pulsed arterial spin labeling. Regional brain activations during dehydration, thirst, and postdrinking were consistent with the network previously identified during systemic hypertonic infusions, thus providing further evidence that the network is involved in monitoring body fluid and the experience of thirst. rCBF measurements in the ventral lamina terminalis were correlated with whole brain rCBF measures to identify regions that correlated with the osmoreceptive region. Regions implicated in the experience of thirst were identified including cingulate cortex, prefrontal cortex, striatum, parahippocampus, and cerebellum. Furthermore, the correlation of rCBF between the ventral lamina terminalis and the cingulate cortex and insula was different for the states of thirst and recent drinking, suggesting that functional connectivity of the ventral lamina terminalis is a dynamic process influenced by hydration status and ingestive behavior.

Impaired inhibition of prepotent motor tendencies in Friedreich ataxia demonstrated by the Simon interference task.

Friedreich ataxia (FRDA) is the most common of the genetically inherited ataxias. We recently demonstrated that people with FRDA have impairment in motor planning - most likely because of pathology affecting the cerebral cortex and/or cerebello-cortical projections. We used the Simon interference task to examine how effective 13 individuals with FRDA were at inhibiting inappropriate automatic responses associated with stimulus-response incompatibility in comparison with control participants. Participants had to respond to arrow targets according to two features which were either congruent or incongruent. We found that individuals with FRDA were differentially affected in reaction time to incongruent, compared with congruent stimuli, when compared with control participants. There was a significant negative correlation between age of onset and the incongruency effect, suggesting an impact of FRDA on the developmental unfolding of motor cognition, independent of the effect of disease duration. Future neuroimaging studies will be required to establish whether this dysfunction is due to cerebellar impairment disrupting cerebro-ponto-cerebello-thalamo-cerebral loops (and thus cortical function), direct primary cortical pathology, or a possible combination of the two.

Resuscitation quality assurance for out-of-hospital cardiac arrest--setting-up an ambulance defibrillator telemetry network.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a leading cause of pre-hospital mortality. Chest compressions performed during cardiopulmonary resuscitation aim to provide adequate perfusion to the vital organs during cardiac arrest. Poor resuscitation technique and the quality of pre-hospital CPR influences outcome from OHCA. Transthoracic impedance (TTI) measurement is a useful tool in the assessment of the quality of pre-hospital resuscitation by ambulance crews but TTI telemetry has not yet been performed in the United Kingdom. We describe a pilot study to implement a data network to collect defibrillator TTI data via telemetry from ambulances. METHODS: Prospective, observational pilot study over a 5-month period. Modems were fitted to 40 defibrillators on ambulances based in Edinburgh. TTI data was sent to a receiving computer after resuscitation attempts for OHCA. RESULTS: 58 TTI traces were transmitted during the pilot period. Compliance with the telemetry system was high. The mean ratio of chest compressions was 73% (95% CI 69-77%), the mean chest compression rate was 128 (95% CI 122-134). The mean time interval from chest compression interruption to shock delivery was 27 s (95% CI 22-32 s). CONCLUSION: Trans-thoracic impedance analysis is an effective means of recording important measures of resuscitation quality including the hands-on-the-chest time, compression rate and defibrillation interval time. TTI data transmission via telemetry is straightforward, efficient and allows resuscitation data to be captured and analysed from a large geographical area. Further research is warranted on the impact of post-resuscitation reporting on the quality of resuscitation delivered by ambulance crews.

Investigation of the effect of anode/filter materials on the dose and image quality of a digital mammography system based on an amorphous selenium flat panel detector.

A comparison, in terms of image quality and glandular breast dose, was carried out between two similar digital mammography systems using amorphous selenium flat panel detectors. The two digital mammography systems currently available from Lorad-Hologic were compared. The original system utilises Mo/Mo and Mo/Rh as target/filter combinations, while the new system uses W/Rh and W/Ag. Images of multiple mammography phantoms with simulated compressed breast thicknesses of 4 cm, 5 cm and 6 cm and various glandular tissue equivalency were acquired under different spectral conditions. The contrast of five details, corresponding to five glandular compositions, was calculated and the ratio of the square of the contrast-to-noise ratio to the average glandular dose was used as a figure-of-merit (FOM) to compare results. For each phantom thickness and target/filter combination, there is an optimum voltage that maximises the FOM. Results show that the W/Rh combination is the best choice for all the detection tasks studied, but for thicknesses greater than 6 cm the W/Ag combination would probably be the best choice. In addition, the new system with W filter presents a better optimisation of the automatic exposure control in comparison with the original system with Mo filter.