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Magnetic resonance imaging (MRI) is a cornerstone in multiple sclerosis (MS) diagnostics and monitoring. Ultra-high field (UHF) MRI is being increasingly used and becoming more accessible. Due to the small diameter and mobility of the spinal cord, imaging this structure at ultra-high fields poses additional challenges compared to brain imaging. Here we review the potential benefits for the MS field by providing a literature overview of the use UHF spinal cord MRI in MS research and we elaborate on the challenges that are faced. Benefits include increased signal- and contrast-to-noise, enabling for higher spatial resolutions, which can improve MS lesion sensitivity in both the spinal white matter as well as grey matter. Additionally, these benefits can aid imaging of microstructural abnormalities in the spinal cord in MS using advanced MRI techniques like functional imaging, MR spectroscopy and diffusion-based techniques. Technical challenges include increased magnetic field inhomogeneities, distortions from physiological motion and optimalisation of sequences. Approaches including parallel imaging techniques, real time shimming and retrospective compensation of physiological motion are making it increasingly possible to unravel the potential of spinal cord UHF MRI in the context of MS research.

Transferability of species distribution models (SDMs) is key to predicting invasion patterns and can be challenged if niche shift occurs in the invaded range. When using native occurrences to estimate potential invasions with presence-only modeling methods, it is important to constrain the pseudo-absence (PA) sampling to the species’ native range. However, some studies including highly cited ones, do not follow this approach to selecting PA samples. In this research, we addressed two questions using an invasive species in the United States (U.S.), kudzu bug (Megacopta cribraria): 1) is model transferability challenged by a non-adaptive niche shift? and 2) is model performance affected by use of PA samples from outside the native range of the species? Kudzu bug is native to Asia, with recently observed non-adaptive niche shift in the U.S. To answer the first question, we quantified the environmental space anisotropy and non-adaptive niche change, and then evaluated the performances of seven SDMs. To answer the second question, we further compared the interpolation and transferability of seven SDMs trained with PAs from the native range and from both native and invaded ranges. We confirmed that the environmental space anisotropy (P = 0.01) and non-adaptive niche change (P = 0.01) are both statistically significant. Of the seven SDMs used, four models had transferability indices higher than 0.9. Boosted regression tree and random forests both had good interpolation and transferability (AUC>0.80 and kappa>0.60), whereas three other models showed good interpolation and fair transferability (AUC>0.70 and kappa>0.40). Inclusion of pseudo-absences from the invaded range significantly increased the interpolation (P

Hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an invasive pest causing significant mortality to eastern and Carolina hemlock in eastern North America. Since 2003, management of HWA has included targeted release of the HWA predator Laricobius nigrinus Fender (Coleoptera: Derodontidae), native to western North America. Establishment of L. nigrinus at release sites is well documented, but investigations of its impact on HWA populations have been limited. A four-year (2014-2018), two-phase study using predator exclusion cages to assess the impact of L. nigrinus on HWA was conducted at nine previous release sites in the eastern United States. Significantly more HWA sistens ovisacs were disturbed on no-cage and open-cage branches than on caged branches where predators were excluded. Mean disturbance levels on cage, no-cage and open-cage branches was 8, 38, and 27 percent, respectively. Seven of nine sites had a mean HWA ovisac disturbance greater than 50% for at least one year. Winter temperatures were also a significant factor in overall mortality of the sistens generation with a mean of 46% on study branches. Six of nine sites had a mean overall mortality (winter mortality and predation) greater than 80% for at least one year. Larvae of Laricobius spp. were recovered at all sites during this study. Sequencing of the COI gene from recoveries in Phase One (2015 and 2016) indicated that 88% were L. nigrinus and 12% were L. rubidus LeConte. Microsatellite analysis performed during Phase Two (2017 and 2018) indicated that approximately 97% of larval recoveries were L. nigrinus, 2% were hybrids of L. nigrinus and L. rubidus, and 1% were L. rubidus. Results of this study suggest that L. nigrinus can significantly impact the HWA sistens generation ovisacs and continued investment in the use of this species as a biological control is recommended. USDA Forest Service cooperative agreementUnited States Department of Agriculture (USDA)United States Forest Service [14-CA-11420004-028] We gratefully acknowledge the assistance of Dr. Thomas Kuhar and Dr. Douglas Pfieffer (Virginia Tech) for review of this project, as well as Dr. Carlyle Brewster (Virginia Tech) for assistance with data analysis. We thank Dr. Nathan Havill (USDA Forest Service), Kari Stanley (Virginia Tech), and Melissa Fischer (Washington State Department of Natural Resources) for assistance with molecular protocols, as well as Mark Mayer (New Jersey Department of Agriculture), Scott Passwaters (James River State Park), Biff Thompson (Maryland Department of Agriculture), Jesse Webster (Great Smoky Mountains National Park), and the staff at Blackberry Farm (Tennessee) for site assistance. Thank you to Arthur Morgan School, Celo Community, and the Chattahoochee National Forest for permission to use sites in NC and GA. We are grateful to Natalie Morris, Kara Jeffries, Andy Dechaine, Ryan Mays, Ashley Toland, and James Wahls (Virginia Tech), Bryan Mudder and Andrew Tait (USDA Forest Service), David Bechtel, Philip Hensley, Elizabeth McCarty, Forest Palmer, Pat Parkman, and David Paulsen (University of Tennessee), and Peter Menzies, Marika Lapham, and Ivy Haas (University of North Carolina Asheville), for laboratory and field assistance. This work was funded under USDA Forest Service cooperative agreement 14-CA-11420004-028. Public domain – authored by a U.S. government employee

Cost-effective strategies to maintain healthy active lifestyle in aging populations are required to address the global burden of age-related diseases. ASPREE will examine whether the potential primary prevention benefits of low dose aspirin outweigh the risks in older healthy individuals. Our primary hypothesis is that daily oral 100. mg enteric-coated aspirin will extend a composite primary endpoint termed 'disability-free life' including onset of dementia, total mortality, or persistent disability in at least one of the Katz Activities of Daily Living in 19,000 healthy participants aged 65. years and above ('US minorities') and 70. years and above (non-'US minorities'). ASPREE is a double-blind, randomized, placebo-controlled trial of oral 100. mg enteric-coated acetyl salicylic acid (ASA) or matching placebo being conducted in Australian and US community settings on individuals free of dementia, disability and cardiovascular disease (CVD) events. Secondary endpoints are all-cause and cause specific mortality, fatal and non-fatal cardiovascular events, fatal and non-fatal cancer (excluding non-melanoma skin cancer), dementia, mild cognitive impairment, depression, physical disability, and clinically significant bleeding. To 20 September 2013 14,383 participants have been recruited. Recruitment and study completion are anticipated in July 2014 and December 2018 respectively. In contrast to other aspirin trials that have largely focused on cardiovascular endpoints, ASPREE has a unique composite primary endpoint to better capture the overall risk and benefit of aspirin to extend healthy independent lifespan in older adults in the US and Australia.

There has been little study to date of daily variation in cardiac death in dialysis patients and whether such variation differs according to dialysis modality and session frequency.Observational cohort study using ANZDATA (Australia and New Zealand Dialysis and Transplant) Registry data.All adult patients with end-stage kidney failure treated by dialysis in Australia and New Zealand who died between 1999 and 2008.Timing of death (day of week), dialysis modality, hemodialysis (HD) session frequency, and demographic, clinical, and facility variables.Cardiac and noncardiac mortality.14,636 adult dialysis patients died during the study period (HD, n = 10,338; peritoneal dialysis [PD], n = 4,298). Cardiac death accounted for 40% of deaths and was significantly more likely to occur on Mondays in in-center HD patients receiving 3 or fewer dialysis sessions per week (n = 9,503; adjusted OR, 1.26; 95% CI, 1.14-1.40; P0.001 compared with the mean odds of cardiac death for all days of the week). This daily variation in cardiac death was not seen in PD patients, in-center HD patients receiving more than 3 sessions per week (n = 251), or home HD patients (n = 573). Subgroup analyses showed that deaths related to hyperkalemia and myocardial infarction also were associated with daily variation in risk in HD patients. This pattern was not seen for vascular, infective, malignant, dialysis therapy withdrawal, or other deaths.Limited covariate adjustment. Residual confounding and coding bias could not be excluded. Possible type 2 statistical error due to limited sample size of home HD and enhanced-frequency HD cohorts.Daily variation in the pattern of cardiac deaths was observed in HD patients receiving 3 or fewer dialysis sessions per week, but not in PD, home HD, and HD patients receiving more than 3 sessions per week.

Polycrystalline diamond cutters (PDC) were sintered with magnesium carbonate (MgCO 3 ) around 8 GPa and 2200–2400 °C in a single-stage cubic anvil press. Different analyzing techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were applied to characterize the micro-structure, sintering behavior, and composition of the diamond-MgCO 3 system. Wear resistance, thermal stability, and rupture strength of MgCO 3 -sintered PDC were compared against conventional cobalt-sintered PDC. An improvement in performance was observed from our laboratory tests, which may enable MgCO 3 -sintered PDC to be a functional superhard material for the cutting, drilling, and machining industries.

Background Determinants and outcomes of peritoneal dialysis (PD)-associated peritonitis occurring within 4 weeks of completion of therapy of a prior episode caused by the same (relapse) or different organism (recurrence) recently have been characterized. However, determinants and outcomes of peritonitis occurring more than 4 weeks after treatment of a prior episode caused by the same (repeated) or different organism (nonrepeated) are poorly understood. Study Design Observational cohort study using Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data. Setting & Participants All Australian PD patients between October 1, 2003, and December 31, 2007, with first episodes of repeated or nonrepeated peritonitis. Predictors Repeated versus nonrepeated peritonitis, according to International Society of PD (ISPD) criteria. Outcomes & Measurements Relapse, hospitalization, catheter removal, hemodialysis transfer, and death. Results After a peritonitis episode, the probability that a subsequent episode represented repeated rather than nonrepeated peritonitis was highest in the second month (41%), then progressively decreased to a stable level of 14% from 6 months onward. When first episodes of repeated (n = 245) or nonrepeated peritonitis (n = 824) were analyzed, repeated peritonitis was predicted independently by a shorter elapsed time from the prior episode (adjusted OR per day elapsed, 0.91; 95% CI, 0.88-0.94). Staphylococcus aureus and coagulase-negative staphylococcus were isolated more frequently in repeated peritonitis, whereas Gram-negative, streptococcal, and fungal organisms were recovered more frequently in nonrepeated peritonitis. Using multivariate logistic regression, repeated peritonitis was associated independently with higher relapse (OR, 5.41; 95% CI, 3.72-7.89) and lower hospitalization rates (OR, 0.63; 95% CI, 0.46-0.85), but catheter removal, hemodialysis transfer, and death rates similar to nonrepeated peritonitis. Limitations Limited covariate adjustment. Residual confounding and coding bias could not be excluded. Conclusions Repeated and nonrepeated peritonitis episodes are caused by different spectra of micro-organisms and have different outcomes. Study findings suggest that the ISPD definition for repeated peritonitis should be limited to 6 months.

Subcortical nuclei are increasingly targeted for deep brain stimulation (DBS) and for gene transfer to treat neurological and psychiatric disorders. For a successful outcome in patients, it is critical to place DBS electrodes or infuse viral vectors accurately within targeted nuclei. However current MRI approaches are still limited to localize brainstem and basal ganglia nuclei accurately. By combining ultra-high resolution structural MRI and contrast-enhanced MRI using iron oxide nanoparticles at high field (3 T and 7 T), we could precisely locate the subcortical nuclei, in particular the subthalamic nucleus in macaques, and validate this location by intracranial electrophysiological mapping. The present data pave the way to a clinical application.

Non-Pseudomonas Gram-negative (NPGN) peritonitis is a frequent, serious complication of peritoneal dialysis; however, previous reports have been limited to small, single-center studies. To gain insight on the frequency, predictors, treatment, and outcomes of NPGN peritonitis, we analyzed data in the ANZDATA registry of all adult Australian peritoneal dialysis patients over a 39-month period using multivariate logistic and multilevel Poisson regressions. There were 837 episodes of NPGN peritonitis (23.3% of all peritonitis) that occurred in 256 patients. The most common organism isolated was Escherichia coli, but included Klebsiella, Enterobacter, Serratia, Acinetobacter, Proteus, and Citrobacter, with multiple organisms identified in a quarter of the patients. The principal risk factor was older age, with poorer clinical outcome predicted by older age and polymicrobial peritonitis. The overall antibiotic cure rate was 59%. NPGN peritonitis was associated with significantly higher risks of hospitalization, catheter removal, permanent transfer to hemodialysis, and death compared to other organisms contributing to peritonitis. Underlying bowel perforation requiring surgery was uncommon. Hence, we show that NPGN peritonitis is a frequent, serious complication of peritoneal dialysis, which is frequently associated with significant risks, including death. Its cure with antibiotics alone is less likely when multiple organisms are involved.

Fungal peritonitis is a serious complication of peritoneal dialysis but previous reports on this have been limited to small, single-center studies. Using all Australian peritoneal dialysis patients, we measured predictors, treatments, and outcomes of this condition by logistic regression and multilevel, multivariate Poisson regression. This encompassed 66 centers over a 4-year period that included 162 episodes of fungal peritonitis (4.5% of all peritonitis episodes) that occurred in 158 individuals. Candida albicans (25%) and other Candida species (44%) were the most common fungi isolated. Fungal peritonitis was independently predicted by indigenous race and prior treatment of bacterial peritonitis. Peritonitis episodes occurring after 7 and 60 days of treatment for previous bacterial peritonitis decreases in the probability of fungal peritonitis 23 and 6%, respectively. Compared with other organisms, fungal peritonitis was associated with significantly higher rates of hospitalization, catheter removal, transfer to permanent hemodialysis, and death. The risks of repeat fungal peritonitis and death were lowest with catheter removal combined with antifungal therapy when compared to either intervention alone. Our study shows that fungal peritonitis is a serious complication of peritoneal dialysis and should be strongly suspected in the context of recent antibiotic treatment for bacterial peritonitis.

Background Primary hepatitis B virus (HBV) vaccination through the intramuscular (IM) route is less efficacious in dialysis patients than in the general population. Previous studies suggest improved seroconversion with intradermal (ID) vaccination. Study Design Prospective open-label randomized controlled trial. Setting & Participants Hemodialysis patients nonresponsive to primary HBV vaccination. Intervention Revaccination with either ID (5 μg of vaccine every week for 8 weeks) or IM (40 μg of vaccine at weeks 1 and 8) HBV vaccine. Outcomes Primary outcome: proportion of patients achieving HBV surface antibody (anti-HBs) titer of 10 IU/L or greater within 2 months of vaccination course. Secondary outcomes: time to seroconversion, predictors of seroconversion, peak antibody titer, duration of seroprotection, and safety and tolerability of vaccine. Measurements Anti-HBs titer to 24 months. Results 59 patients were analyzed. Seroconversion rates were 79% ID versus 40% IM (P = 0.002). The unadjusted odds ratio for seroconversion for ID versus IM was 5.5 (95% confidence interval [CI], 1.6 to 18.4) and increased with adjustment for baseline differences. The only factor predictive of seroconversion was the ID vaccination route. The geometric mean peak antibody titer was significantly greater in the ID versus IM group: 239 IU/L (95% CI, 131 to 434) versus 78 IU/L (95% CI, 36 to 168; P Limitations Inability to distinguish whether the mechanism of the greater efficacy of ID vaccination was the cumulative effect of multiple injections or route of administration; use of anti-HBs as a surrogate marker of protection; lack of evidence of long-term protection. Conclusions Significantly greater seroconversion rates and peak antibody titers can be achieved with ID compared with IM vaccination in hemodialysis patients nonresponsive to primary vaccination. ID vaccination should become the standard of care in this setting.

The aim of the present investigation is to compare rates, types, causes, and timing of infectious death in incident peritoneal dialysis (PD) and hemodialysis (HD) patients in Australia and New Zealand.Observational cohort study using the Australian and New Zealand Dialysis and Transplant Registry data.The study included all patients starting dialysis therapy between April 1, 1995, and December 31, 2005.Dialysis modality.Rates of and time to infectious death were compared by using Poisson regression, Kaplan-Meier, and competing risks multivariate Cox proportional hazards model analyses.21,935 patients started dialysis therapy (first treatment PD, n = 6,020; HD, n = 15,915) during the study period, and 1,163 patients (5.1%) died of infectious causes (PD, 529 patients; 7.6% versus HD, 634 patients; 4.2%). Incidence rates of infectious mortality in PD and HD patients were 2.8 and 1.7/100 patient-years, respectively (incidence rate ratio PD versus HD, 1.66; 95% confidence interval [CI], 1.47 to 1.86). After performing competing risks multivariate Cox analyses allowing for an interaction between time on study and modality because of identified nonproportionality of hazards, PD consistently was associated with increased hazard of death from infection compared with HD after 6 months of treatment (6 months hazard ratio [HR], 1.08; 95% CI, 0.76 to 1.54; 6 months to 2 years HR, 1.31; 95% CI, 1.09 to 1.59; 2 to 6 years HR, 1.51; 95% CI, 1.26 to 1.80;6 years HR, 2.76; 95% CI, 1.76 to 4.33). This increased risk of infectious death in PD patients was largely accounted for by an increased risk of death caused by bacterial or fungal peritonitis.Patients were not randomly assigned to their initial dialysis modality. Residual confounding and coding bias could not be excluded.Dialysis modality selection significantly influences risks, types, causes, and timing of fatal infections experienced by patients with end-stage kidney disease in Australia and New Zealand.

Functional magnetic resonance imaging (fMRI) has become a powerful tool for studying the normal and diseased human brain. The application of fMRI in detecting neuronal signals in the trigeminal system, however, has been hindered by low detection sensitivity due to activation artifacts caused by cardiac pulse-induced brain and brainstem movement. A variety of cardiac gating techniques have been proposed to overcome this issue, typically by phase locking the sampling to a particular time point during each cardiac cycle. We sought to compare different cardiac gating strategies for trigeminal system fMRI. In the present study, we used tactile stimuli to elicit brainstem and thalamus activation and compared the fMRI results obtained without cardiac gating and with three different cardiac gating strategies: single-echo with TR of 3 or 9 heartbeats (HBs) and dual-echo T2*-mapping EPI (TR = 2 HBs, TE = 21/55 ms). The dual-echo T2* mapping and the single-echo with TR of 2 and 3 HBs cardiac-gated fMRI techniques both increased detection rate of fMRI activation in brainstem. Activation in the brainstem and the thalamus was best detected by cardiac-gated dual-echo EPI.

Elevated white cell count at commencement of peritoneal dialysis predicts overall and cardiac mortality.BackgroundHigher total white blood cell counts (WCC) have been shown in the general population to be strongly and independently predictive of coronary heart disease and all-cause mortality. The aim of the present study was to evaluate the prognostic value of WCC in patients commencing peritoneal dialysis (PD).MethodsA cohort of 323 patients (mean age 55.1 ± 17.7 years, 54% male, 81% Caucasian) commencing PD at the Princess Alexandra Hospital between January 1, 1998 and March 31, 2003 were prospectively followed until death, completion of PD therapy, or otherwise to the end of the study (January 2, 2004), at which point data were censored. Individuals with failed renal transplants (N = 17) and those with acute infections at the time of PD onset (N = 12) were not included. A multivariate Cox's proportional hazards model was applied to calculate hazard ratios and adjusted survival curves for time to death or cardiac death, adjusting for baseline demographic, clinical, and laboratory characteristics.ResultsMedian actuarial patient survival was 3.9 years [95% confidence interval (CI) 3.2–4.7 years]. The highest quartile of WCC (>9.4 × 109/L) was significantly and independently associated with increased risks of both death from all causes [adjusted hazard ratio (HR) 2.27, 95% CI 1.09–4.74, P < 0.05] and cardiac death (HR 3.75, 95% CI 1.2–11.8, P < 0.05). Other adverse risk factors included older age, lower serum albumin, and the presence of coronary artery disease. Similar associations were found between mortality and PMN count, but not lymphocyte count.ConclusionElevated baseline WCC or PMN count at the commencement of PD (in the absence of acute infection) strongly predicts all-cause and cardiovascular mortality. These data suggest that new PD patients with higher WCC may warrant closer monitoring and extra attention to modifiable cardiovascular risk factors.

The feasibility of recording event-related potentials (ERP) during functional MRI (fMRI) scanning using higher level cognitive stimuli was studied. Using responses to illusory figures in a visual oddball task, evoked potentials were obtained with their expected configurations and latencies. A rapid stimulation scheme using randomly varied trial lengths was employed, and class-wise characteristics of the hemodynamic response were obtained by a nonlinear analysis of the fMRI time series. Implications and limitations of conducting combined ERP-fMRI experiments using higher level cognitive stimuli are discussed. EEG/fMRI results revealed a sequential activation of striate and extrastriate occipital cortex along the ventral path of object processing for Kanizsa figures. Interestingly, Kanizsa figures activated the human motion area MT. Targets resulted in activations of frontal and parietal cortex which were not activated for standard stimuli.

A precision radio-frequency (RF) transverse modulation technique based on a resonant tunnel diode oscillator (TDO) has been used to study the dynamic transverse susceptibility in novel single domain Fe nanoparticles synthesized using reverse-micelle chemistry. The RF data exhibits peaks at characteristic anisotropy fields. In addition, the dynamic susceptibility shows remarkable consistency with static magnetic measurements (MH) done using a SQUID magnetometer. Overall, these RF experiments are well suited to probe the magnetic anisotropy in nanophase materials.

By utilizing the sequential synthesis afforded reverse micelles, nanocomposite materials can be synthesized which have a diamagnetic core surrounded by a thin shell of ferromagnetic material passivated with a second shell of a diamagnet. Using gold as the diamagnetic material and iron as the ferromagnetic material, nanocomposites can be synthesized where there is a thin layer of the magnetic material, which is passivated and protected from oxidation. In this case, all of the spins of the magnetic layer lie within the surface of the particle. Magnetic properties were measured for nanophase particles using SQUID magnetometry. The particles, which consist of a 6 nm core of gold, coated with a 1 nm thick iron layer and passivated with an outer shell of gold, are superparamagnetic with a blocking temperature of 45 K and coercivity at 10 K of 400 Oe. These results are similar to magnetic properties of 8 nm iron particles coated with gold, where blocking temperature is 50 K and coercivity is 400 Oe. This suggests that in nanoparticles the spins that define the outer surface are responsible for the magnetic properties.

The introduction of microbubble suspensions represents a new class of contrast agents for enhancement of vascular imaging in ultrasound. The effective ingredients of this class of contrast agents are acoustically active and produce micrometer-sized inhomogeneities in the blood pool. The microbubbles interact with the sound field either by scattering the incident sound beam or by oscillations that produce resonance, which at higher acoustic power can lead to the destruction of the microbubbles. Different processing of the various microbubble echo responses led to a number of new imaging modes that exhibit varying sensitivity and specificity for microbubble detection, of which the nonlinear scatter during destruction (“stimulated acoustic emission”) is the most sensitive, enabling the detection of a single microbubble in a capillary bed. With these techniques, the visualization of organ perfusion with ultrasound became possible. These agents are characterized not only by their physicochemical uniqueness but also by their unique pharmaceutical properties. All microbubble contrast agents can be considered to be “particulates,” which, by nature of their size, remain in the blood pool until the gas is dissolved or until they are sequestered by the reticulendothelial system (RES). Their character as blood pool agents makes them ideally suited for enhancing vascular imaging. The galactose–based agent Levovist (Schering AG, Berlin, Germany) was the first microbubble agent to enter the market with sufficient stability to provide enhancement of the total body blood pool following intravenous (IV) injection. Due to the particulate character, the risk profile of this new class of agents differs from contrast agents for x-ray or magnetic resonance imaging (MRI). The theoretical risks are generated by the tolerance of the tracer medium, its osmolality, the microbubble shell material, and the microbubble particles themselves. Gas bubbles may grow either by coalescence or by inward diffusion of gases, potentially occluding small vessels in the lung and periphery. In addition, microbubbles provide a theoretical nidus for cavitation. The purpose of this article is to report the broader experience in clinical routine as regards the safety of this new class of contrast agents.

The DeVilbiss Ultraneb 99 ultrasonic nebuliser is frequently used for sputum induction in AIDS patients undergoing investigation of suspected Pneumocystis carinii pneumonia. We set out to characterise this machine under a wide range of operating conditions so that the efficiency of the technique might be optimised. The range and frequency of particle sizes remained reasonably constant and gave a Gaussian distribution pattern (mean MMD = 5.05 μm, SD = 0.34 μm) below a critical volume of nebulised solution, this volume being related to the intensity setting of the nebuliser. Beyond this volume, the particle size distribution adopted a bimodal pattern, and nebuliser output subsequently tailed off altogether. The volume of couplant within the nebuliser chamber was critical for efficient nebuliser output. Changes in surface tension and tonicity of solution to be nebulised did not affect the performance of the nebuliser substantially. Successful sputum induction may rely on both proximal and distal airway deposition, which may be enhanced by changes in both the nebuliser and nebulised solution.

Simple tests of lung function may be misleading in the assessment of patients with interstitial lung disease. Eight patients are described with cryptogenic fibrosing alveolitis (histologically proven in four) with severe breathlessness and low gas transfer (median DLCO 32.4%, range 9.2 to 35.3%, % predicted) in whom lung volumes were preserved [median VC 98.7, range 67.5-131.1%; median TLC 92.5, range 88.1 to 121.2, (% predicted)], and in whom there was no evidence of airflow obstruction [median FEV1/FVC 84.6, range 68-116 (% predicted)]. All were current or ex-heavy smokers. Thoracic high resolution computed tomography revealed upper zone emphysema, the extent of which was not appreciated using conventional chest radiography. The atypical physiological and radiological features can be explained by coincidental cryptogenic fibrosing alveolitis and emphysema and high resolution computed tomography was valuable in the assessment of these patients.

Objectifs Presenter notre experience initiale en neuro-imagerie anatomique en IRM a 7T (contraste T1, T2*), en comparaison avec 3T et 1,5T. Materiels et methodes Neurospin est equipe d’un imageur 7T Siemens (le 1er en France), avec des gradients de 80 mT, une antenne en quadrature et une antenne 8 canaux. La comparaison a porte sur les images ponderees Tl et T2* en haute resolution spatiale des structures sous-corticales normales (hippocampe, noyaux gris centraux), chez 20 sujets, avec mesure du rapport contraste sur bruit (CNR). Resultats En contraste T2*, le CNR sur l’hippocampe est multiplie par 5 entre 1,5 et 7T, et par 2,5 entre 3 et 7T. L’excellent CNR a 7T associe a l’amelioration de la resolution spatiale (0,4 * 0,4 * 1,2 mm3) permet de visualiser des details anatomiques non visibles a champ clinique (ex structure interne de la corne d’Ammon, microvascularisation des noyaux gris centraux…). En contraste Tl, l’heterogeneite du champ Bl et l’allongement de Tl limitent le gain potentiel du passage a 7T. Conclusion L’imagerie a 7T offre des perspectives nouvelles pour le diagnostic des pathologies cerebrales (Alzheimer, Parkinson, epi-lepsie, demences vasculaires…) grâce a de nouveaux contrastes en T2* et a une resolution spatiale inegalee. La maitrise progressive de certains artefacts lies au champ permettra d’ameliorer grandement l’imagerie en T1.

Objectifs Presenter notre experience initiale en neuro-imagerie anatomique en IRM a 7T (contraste Tl, T2*), en comparaison avec 3T et 1,5T. Materiels et methodes Neurospin est equipe d’un imageur 7T Siemens (le 1er en France), avec des gradients de 80 mT, une antenne en quadrature et une antenne 8 canaux. La comparaison a porte sur les images ponderees Tl et T2* en haute resolution spatiale des structures sous-corticales normales (hippocampe, noyaux gris centraux), chez 20 sujets, avec mesure du rapport contraste sur bruit (CNR). Resultats En contraste T2*, le CNR sur l’hippocampe est multiplie par 5 entre 1,5 et 7T, et par 2,5 entre 3 et 7T. L’excellent CNR a 7T associe a l’amelioration de la resolution spatiale (0,4*0,4*1,2 mm 3 ) permet de visualiser des details anatomiques non visibles a champ clinique (ex structure interne de la corne d’Ammon, microvascularisation des noyaux gris centraux... ). En contraste T1, l’heterogeneite du champ B let l’allongement de T1 limitent le gain potentiel du passage a 7T. Conclusion L’imagerie a 7T offre des perspectives nouvelles pour le diagnostic des pathologies cerebrales (Alzheimer, Parkinson, epilepsie, demences vasculaires ... ) grâce a de nouveaux contrastes en T2* et a une resolution spatiale inegalee. La maitrise progressive de certains artefacts lies au champ permettra d’ameliorer grandement l’imagerie en Tl.

The use of nebulized lignocaine, with and without intravenous diazepam premedication, was compared with lignocaine given by bolus in 52 patients undergoing fibreoptic bronchoscopy (FOB). Changes in airflow, cardiac rhythm, and transcutaneous PO2 were recorded, and patient acceptability, blood lignocaine levels, and the duration of the procedure were also monitored. Nebulized lignocaine alone provide adequate anaesthesia and the procedures were performed more quickly (P less than 0.05) than when bolus lignocaine was used. Nebulized lignocaine without diazepam was acceptable to the patients and was not associated with the significant (P less than 0.03) falls in transcutaneous PO2 which followed diazepam administration. Nebulized lignocaine, with and without, diazepam premedication is a safe, effective and acceptable method of inducing topical anaesthesia for FOB.

Parenteral theophylline usage was studied in 53 patients with worsening airflow obstruction who had been prescribed slow release theophylline drugs and were admitted to a hospital lacking facilities for rapid serum theophylline concentration estimation. Individual clinicians varied in their practice with respect to parenteral aminophylline, but in general its use was favoured in patients with asthma rather than simple chronic airflow obstruction. There was no significant difference in admission serum theophylline concentrations between 31 patients who were subsequently given intravenous aminophylline and 22 who were not. There was also no significant difference in admission serum theophylline concentrations between ten patients given an aminophylline bolus and an infusion, seven patients given a bolus alone and 14 patients given an infusion alone. Individual patient's serum theophylline concentrations were variable during infusions and often suboptimal. The results indicate that the use of parenteral aminophylline in patients receiving slow release theophyllines is imprecise and possibly hazardous without facilities for prompt serum theophylline concentration estimations. This facility should be available in hospitals where parenteral aminophylline is used.

Inclusive proton spectra have been measured over the angular range 25° – 150° for 164 MeV protons on 27 Al, 58 Ni, 62 Ni and 208 Pb. At 25° and 30° a peak attributable to quasi-free scattering, accounting for ≈20% of the total number of fast protons at these angles, is present. No quasi-free peak is evident in the spectra at larger angles. These results are in disagreement with previously published work at this energy but in line with results reported at other energies.