Search results for "type"
showing 10 items of 10618 documents
Association of vitamin D serum levels and its common genetic determinants, with severity of liver fibrosis in genotype 1 chronic hepatitis C patients.
2013
Background and aims: Lower 25-Hydroxyvitamin D (25[OH]D) serum lev- els have been associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients (G1CHC). In addition, a recent genome-wide study identified genetic variants (rs12785878, near dehydrocholesterol reduc- tase, DHCR7; rs10741657, near CYP2R1; and rs7041, near vitamin D binding protein, GC) affecting 25(OH)D serum levels in healthy populations. We aimed to assess the association between vitamin D serum levels and its genetic determinants, with the severity of liver fibrosis. Material and methods: Two hundred sixty patients with biopsy-proven G1CHC were consecutively evaluated. The 25(OH)D serum levels wer…
Vitamin A deficiency alters rat lung alveolar basement membrane: reversibility by retinoic acid.
2010
Vitamin A is essential for lung development and pulmonary cell differentiation and its deficiency results in alterations of lung structure and function. Basement membranes (BMs) are also involved in those processes, and retinoic acid, the main biologically active form of vitamin A, influences the expression of extracellular matrix macromolecules. Therefore, we have analyzed the ultrastructure and collagen content of lung alveolar BM in growing rats deficient in vitamin A and the recovering effect of all-trans retinoic acid. Male weanling pups were fed a retinol-adequate or -deficient diet until they were 60 days old. A group of vitamin A-deficient pups were recovered by daily intraperitonea…
Vitamin A deficiency alters the structure and collagen IV composition of rat renal basement membranes.
2005
Retinoids can modulate the expression of extracellular matrix (ECM) proteins with variable results depending on other contributing factors. Because changes in these proteins may alter the composition and impair the function of specialized ECM structures such as basement membranes (BMs), we studied the effects of vitamin A deficiency on renal BMs during the growing period. Newborn male rats were fed a vitamin A-deficient (VAD) diet for 50 d. The ultrastructure of renal BMs was analyzed by electron microscopy. Total collagen IV, the different alpha(IV) chains, matrix degrading metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) were quantified by immunocytochemistry a…
N-3 fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring.
2006
We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring. Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days. Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitami…
α-Tocopherol Modulates Phosphatidylserine Externalization in Erythrocytes
2006
Objective— The aim of the present study was to assess the effect of α-tocopherol, the main vitamin E isomer on phosphatidylserine (PS) exposure at the surface of circulating erythrocytes, and to determine consequences on erythrocyte properties. Methods and Results— In vitro α-tocopherol enrichment of isolated erythrocytes significantly decreased PS externalization as assessed by lower Annexin V-fluorescein isothiocyanate labeling. Plasma phospholipid transfer protein (PLTP) transfers vitamin E, and both α-and γ-tocopherol accumulated in circulating erythrocytes from PLTP-deficient homozygous (PLTP −/− ) mice as compared with wild-type mice. In agreement with in vitro studies, vitamin E–enr…
Conceptual graph operations for formal visual reasoning in the medical domain
2014
International audience; Objective - Conceptual graphs (CGs) are used to represent clinical guidelines because they support visual reasoning with a logical background, making them a potentially valuable representation for guidelines.Materials and methods - Conceptual graph formalism has an essential and basic component: a formal vocabulary that drives all of the other mechanisms, notably specialization and projection. The graph's theoretical operations, such as projection, rules, derivation, constraints, probabilities and uncertainty, support diagrammatic reasoning.Results - A conceptual graph's graphical user interface includes a multilingual vocabulary management, some query and decision-m…
A practical solution to the problem of automatic part-of-speech induction from text
2005
The problem of part-of-speech induction from text involves two aspects: Firstly, a set of word classes is to be derived automatically. Secondly, each word of a vocabulary is to be assigned to one or several of these word classes. In this paper we present a method that solves both problems with good accuracy. Our approach adopts a mixture of statistical methods that have been successfully applied in word sense induction. Its main advantage over previous attempts is that it reduces the syntactic space to only the most important dimensions, thereby almost eliminating the otherwise omnipresent problem of data sparseness.
Genesis of fumarolic emissions as inferred by isotope mass balances: CO 2 and water at Vulcano Island, Italy
2002
We have developed a quantitative model of CO2 and H2O isotopic mixing between magmatic and hydrothermal gases for the fumarolic emissions of the La Fossa crater (Vulcano Island, Italy). On the basis of isotope balance equations, the model takes into account the isotope equilibrium between H2O and CO2 and extends the recent model of chemical and energy two-end-member mixing by Nuccio et al. (1999). As a result, the H2O and CO2 content and the δD, δ18O, and δ13C isotope compositions for both magmatic and hydrothermal end-members have been assessed. Low contributions of meteoric steam, added at a shallow depth, have been also recognized and quantified in the fumaroles throughout the period fro…
Gas emissions from five volcanoes in northern Chile and implications for the volatiles budget of the Central Volcanic Zone
2014
This study performed the first assessment of the volcanic gas output from the Central Volcanic Zone (CVZ) of northern Chile. We present the fluxes and compositions of volcanic gases (H2O, CO2, H2, HCl, HF, and HBr) from five of the most actively degassing volcanoes in this region—Lascar, Lastarria, Putana, Ollague, and San Pedro—obtained during field campaigns in 2012 and 2013. The inferred gas plume compositions for Lascar and Lastarria (CO2/Stot = 0.9–2.2; Stot/HCl = 1.4–3.4) are similar to those obtained in the Southern Volcanic Zone of Chile, suggesting uniform magmatic gas fingerprint throughout the Chilean arc. Combining these compositions with our own UV spectroscopy measurements of …
Forecasting Etna eruptions by real-time observation of volcanic gas composition
2007
It is generally accepted, but not experimentally proven, that a quantitative prediction of volcanic eruptions is possible from the evaluation of volcanic gas data. By discussing the results of two years of real-time observation of H2O, CO2, and SO2 in volcanic gases from Mount Etna volcano, we unambiguously demonstrate that increasing CO2/SO2 ratios can allow detection of the pre-eruptive degassing of rising magmas. Quantitative modeling by the use of a saturation model allows us to relate the pre-eruptive increases of the CO2/SO2 ratio to the refilling of Etna's shallow conduits with CO2-rich deep-reservoir magmas, leading to pressurization and triggering of eruption. The advent of real-ti…