High brightness laser-plasma X-ray source at IFAM : Characterization and applications

A high brightness laser-plasma X-ray source has been set-up and is presently available at IFAM. A wide range of diagnostics has been set up to monitor the properties of the X-ray radiation and to control the main parameters including photon energy, flux intensity, and pulse duration. A beam extractor enables access to the X-ray radiation at atmospheric pressure. A simple, easy-to-use projection microscope has been built which is capable of single-shot micron resolution imaging with digital acquisition. Preliminary biomedical experiments show that the X-ray doses available on a single laser shot exposure of our source fully meet the conditions required for an important class of biological experiments based on X-ray induced DNA damage providing an ideal alternative to the long time exposures needed with X-ray tubes

Increased circulating levels of vitamin D binding protein in MS patients

Vitamin D (vitD) low status is currently considered a main environmental factor in multiple sclerosis (MS) etiology and pathogenesis. VitD and its metabolites are highly hydrophobic and circulate mostly bound to the vitamin D binding protein (DBP) and with lower affinity to albumin, while less than 1\% are in a free form. The aim of this study was to investigate whether the circulating levels of either of the two vitD plasma carriers and/or their relationship are altered in MS. We measured DBP and albumin plasma levels in 28 MS patients and 24 healthy controls. MS patients were found to have higher DBP levels than healthy subjects. Concomitant interferon beta therapy did not influence DBP concentration, and the difference with the control group was significant in both females and males. No significant correlation between DBP and albumin levels was observed either in healthy controls or in patients. These observations suggest the involvement of DBP in the patho-physiology of MS

Grain size distribution uncertainty quantification in volcanic ash dispersal and deposition from weak plumes

We present the results of uncertainty quantification and sensitivity analysis applied to volcanic ash dispersal from weak plumes with focus on the uncertainties associated to the original grain size distribution of the mixture. The Lagrangian particle model Lagrangian Particles Advection Code is used to simulate the transport of inertial particles under the action of realistic atmospheric conditions. The particle motion equations are derived by expressing the particle acceleration as the sum of forces acting along its trajectory, with the drag force calculated as a function of particle diameter, density, shape, and Reynolds number. Simulations are representative of a weak plume event of Mount Etna (Italy) and aimed at quantifying the effect on the dispersal process of the uncertainty in the mean and standard deviation of a lognormal function describing the initial grain size distribution and in particle sphericity. In order to analyze the sensitivity of particle dispersal to these uncertain variables with a reasonable number of simulations, response surfaces in the parameter space are built by using the generalized polynomial chaos expansion technique. The mean diameter and standard deviation of particle size distribution, and their probability density functions, at various distances from the source, both airborne and on ground, are quantified. Results highlight that uncertainty ranges in these quantities are drastically reduced with distance from source, making them largely dependent just on the location. Moreover, at a given distance from source, the distribution is mostly controlled by particle sphericity, particularly on the ground, whereas in air also mean diameter and sorting play a main role

Line spectroscopy with spatial resolution of laser-plasma X-ray emission

High dynamic range, space-resolved X-ray spectra of an aluminum laser–plasma in the 5.5–8 Å range were obtained using a TlAP crystal and a cooled CCD camera as a detector. This technique was used to investigate the emission region in the longitudinal direction over a distance of approximately 350 μm from the solid target surface. These data show that the electron density profile varies by two orders of magnitude with the temperature ranging from about 180 eV in the overdense region to about 650 eV in the underdense region. Accordingly, different equilibria take place across the explored region which can be identified with this experimental technique. Detailed studies on highly ionized atomic species in different plasma conditions can therefore be performed simultaneously under controlled conditions

Atrial natriuretic factor in essential hypertension : echocardiographic and humoral correlates

Aim of this study was to assess the relationship between plasma concentration of atrial natriuretic factor (ANF) and its two-dimensional echocardiographic (left ventricular mass, left atrium diameter) and humoral (plasma renin and aldosterone) variables in essential hypertension (EH). We evaluated 32 patients with uncomplicated mild to moderate EH and 10 controls. They were studied in the supine position after 7 days of constant dietary sodium intake and were off therapy since at least 3 weeks. ANF values overlapped between EH patients and controls (27.8 +/- 11.5 vs. 19.5 +/- 7.4 pg/ml, p = NS). In EH, no significant correlation was found between ANF values and left ventricular mass (r = 0.29), left atrial diameter (r = 0.04), mean arterial blood pressure (r = 0.26), plasma renin activity (r = 0.00), and aldosterone (r = 0.26). In EH, ANF values overlapped between the 15 patients with hypertrophy and the 17 patients with normal ventricular mass: 30.3 +/- 17 vs. 25.6 +/- 10.6 pg/ms (p = NS). We conclude that there is a substantial overlap in plasma ANF values between mild to moderate uncomplicated EH and controls, and left ventricular hypertrophy is not a major independent stimulus to ANF release in EH

Ammonia emissions from a soil amended with urea and inhibitor of urease activity in a Mediterranean area

Urea and ammonium-based fertilisers are nowadays one of the most important sources of ammonia (NH3) emissions to the atmosphere in Europe. However, little is known about NH3 volatilisation in Mediterranean areas. The aim of the present study was the quantification of NH3 emissions by using the Integrated Horizontal Flux (IHF) method after application of urea with the urease inhibitor N-(n-butyl) thiophosphorie triamide (NBPT) to a semiarid agricultural soil. The field experiment was carried out at "La Poveda" field station in Madrid on a sunflower crop in spring 2006. Urea and a mixture of urea and the inhibitor (0.14%) were surfaee-applied by hand at a rate of 170 kg N ha"' to eircular plots (diam. 40 m). The soil was irrigated with 10 mm of water just after the applieation of urea to dissolve and incorporate it onto the first layer of soil. There were three peaks in the NH3 flux over the duration of the measurement period (36 d). The first peak was associated to irrigation and the others to rainfall events. The total NH3 emission during the whole experiment (36 days) was 17.3 ±5.5kgNH3-N ha"1 in the ease of urea treated soils and 10.0 ± 4.5 kg NHrN ha"' where NBPT was ineluded with the urea

Cabergoline, prolactin and heart

Summary Introduction and aim:  Dopamine agonists have been reported to increase the risk of cardiac valve regurgitation in patients with Parkinson's disease. However, it is unknown whether these drugs might be harmful for patients with hyperprolactinaemia (HyperPRL). The aim of the study was to evaluate whether HyperPRL patients treated with dopamine agonists had a higher prevalence of cardiac valves regurgitation than that of general population. Methods and patients:  One hundred consecutive patients (79 women, 21 men, mean age 41 ± 13 years) with HyperPRL during treatment with cabergoline were enrolled in an observational case–control study and compared with 100 matched normal subjects (controls). Valve regurgitation was assessed by echocardiography according to the American Society of Echocardiography recommendations. Results:  Seven HyperPRL patients (7%) and six controls (6%) had moderate (grade 3) regurgitation in any valve (p = 0.980). All were asymptomatic and had no signs of cardiac disease. Mean duration of cabergoline treatment was 67 ± 39 months (range: 3–199 months). Mean cumulative dose of cabergoline was 279 ± 301 mg (range: 15–1327 mg). Moderate valve regurgitation was not associated with the duration of treatment (p = 0.359), with cumulative dose of cabergoline (p = 0.173), with age (p = 0.281), with previous treatment with bromocriptine (p = 0.673) or previous adenomectomy (p = 0.497) in patients with HyperPRL. Discussion:  In conclusion, treatment with cabergoline was not associated with increased prevalence of cardiac valves regurgitation in patients with HyperPRL. Mean cumulative dose of cabergoline was lower in patients with HyperPRL than that reported to be deleterious for patients with Parkinson's disease: hence, longer follow-up is necessary, particularly in patients receiving weekly doses > 3 mg

Liver enlargement predicts obstructive sleep apnea–hypopnea syndrome in morbidly obese women

Obstructive sleep apnea–hypopnea syndrome (OSAHS) is frequently present in patients with severe obesity, but its prevalence especially in women is not well defined. OSAHS and non-alcoholic fatty liver disease are common conditions, frequently associated in patients with central obesity and metabolic syndrome and are both the result of the accumulation of ectopic fat mass. Identifying predictors of risk of OSAHS may be useful to select the subjects requiring instrumental sleep evaluation. In this cross-sectional study, we have investigated the potential role of hepatic left lobe volume (HLLV) in predicting the presence of OSAHS. OSAHS was quantified by the apnea/hypopnea index (AHI) and oxygen desaturation index in a cardiorespiratory inpatient sleep study of 97 obese women [age: 47 ± 11 years body mass index (BMI): 50 ± 8 kg/m2]. OSAHS was diagnosed when AHI was ≥5. HLLV, subcutaneous and intra-abdominal fat were measured by ultrasound. After adjustment for age and BMI, both HLLV and neck circumference (NC) were independent predictors of AHI. OSAHS was found in 72% of patients; HLLV ≥ 370 cm3 was a predictor of OSAHS with a sensitivity of 66%, a specificity of 70%, a positive and negative predictive values of 85 and 44%, respectively (AUC = 0.67, p < 0.005). A multivariate logistic model was used including age, BMI, NC, and HLLV (the only independent predictors of AHI in a multiple linear regression analyses), and a cut off value for the predicted probability of OSAHS equal to 0.7 provided the best diagnostic results (AUC = 0.79, p < 0.005) in terms of sensitivity (76%), specificity (89%), negative and positive predictive values (59 and 95%, respectively). All patients with severe OSAHS were identified by this prediction model. In conclusion, HLLV, an established index of visceral adiposity, represents an anthropometric parameter closely associated with OSAHS in severely obese women

Muscle magnetic resonance imaging in myotonic dystrophy type 1 (DM1) : Refining muscle involvement and implications for clinical trials

Only a few studies have reported muscle imaging data on small cohorts of patients with myotonic dystrophy type 1 (DM1). We aimed to investigate the muscle involvement in a large cohort of patients in order to refine the pattern of muscle involvement, to better understand the pathophysiological mechanisms of muscle weakness, and to identify potential imaging biomarkers for disease activity and severity. One hundred and thirty-four DM1 patients underwent a cross-sectional muscle magnetic resonance imaging (MRI) study. Short tau inversion recovery (STIR) and T1 sequences in the lower and upper body were analyzed. Fat replacement, muscle atrophy and STIR positivity were evaluated using three different scales. Correlations between MRI scores, clinical features and genetic background were investigated. The most frequent pattern of muscle involvement in T1 consisted of fat replacement of the tongue, sternocleidomastoideus, paraspinalis, gluteus minimus, distal quadriceps and gastrocnemius medialis. Degree of fat replacement at MRI correlated with clinical severity and disease duration, but not with CTG expansion. Fat replacement was also detected in milder/asymptomatic patients. More than 80% of patients had STIR-positive signals in muscles. Most DM1 patients also showed a variable degree of muscle atrophy regardless of MRI signs of fat replacement. A subset of patients (20%) showed a 'marbled' muscle appearance. Muscle MRI is a sensitive biomarker of disease severity alsofor the milder spectrum of disease. STIR hyperintensity seems to precede fat replacement in T1. Beyond fat replacement, STIR positivity, muscle atrophy and a 'marbled' appearance suggest further mechanisms of muscle wasting and weakness in DM1, representing additional outcome measures and therapeutic targets for forthcoming clinical trials. We refined the pattern of muscle involvement in DM1 by upper and lower body muscle magnetic resonance imaging (MRI), identifying the most frequent pattern of fat replacement and confirming that muscle MRI is a sensitive biomarker of disease burden in DM1. We also observed: STIR-positive muscles in 80% of patients preceding fat replacement, muscle atrophy in muscles unreplaced by fat, and progeroid muscle appearance supporting a premature muscle senescence. Our findings provide novel insights into the pathophysiological mechanisms of muscle wasting and weakness in DM1, and could represent additional outcome measures and therapeutic targets for forthcoming clinical trials

Comparison of quantitative muscle ultrasound and whole-body muscle MRI in facioscapulohumeral muscular dystrophy type 1 patients

Introduction: Muscle ultrasound is a fast, non-invasive and cost-effective examination that can identify structural muscular changes by assessing muscle thickness and echointensity (EI) with a quantitative analysis (QMUS). To assess applicability and repeatability of QMUS, we evaluated patients with genetically confirmed facioscapulohumeral muscular dystrophy type 1 (FSHD1), comparing their muscle ultrasound characteristics with healthy controls and with those detected by MRI. We also evaluated relationships between QMUS and demographic and clinical characteristics. Materials and methods: Thirteen patients were included in the study. Clinical assessment included MRC sum score, FSHD score and The Comprehensive Clinical Evaluation Form (CCEF). QMUS was performed with a linear transducer scanning bilaterally pectoralis major, deltoid, rectus femoris, tibialis anterior and semimembranosus muscles in patients and healthy subjects. For each muscle, we acquired three images, which were analysed calculating muscle EI by computer-assisted grey-scale analysis. QMUS analysis was compared with semiquantitative 1.5&nbsp;T muscle MRI scale. Results: All muscles in FSHD patients showed a significant increased echogenicity compared to the homologous muscles in healthy subjects. Older subjects and patients with higher FSHD score presented increased muscle EI. Tibialis anterior MRC showed a significant inverse correlation with EI. Higher median EI was found in muscles with more severe MRI fat replacement. Conclusions: QMUS allows quantitative evaluation of muscle echogenicity, displaying a tight correlation with muscular alterations, clinical and MRI data. Although a confirmation on larger sample is needed, our research suggests a possible future application of QMUS in diagnosis and management of muscular disorders