Heme oxygenase-1 as a modulator of intestinal inflammation development and progression

Indexación: Scopus.Heme Oxygenase 1 (HMOX1) is an enzyme that catalyzes the reaction that degrades the heme group contained in several important proteins, such as hemoglobin, myoglobin, and cytochrome p450. The enzymatic reaction catalyzed by HMOX1 generates Fe2+, biliverdin and CO. It has been shown that HMOX1 activity and the by-product CO can downmodulate the damaging immune response in several models of intestinal inflammation as a result of pharmacological induction of HMOX1 expression and the administration of non-toxic amounts of CO. Inflammatory Bowel Diseases, which includes Crohn's Disease (CD) and Ulcerative Colitis (UC), are one of the most studied ailments associated to HMOX1 effects. However, microbiota imbalances and infections are also important factors influencing the occurrence of acute and chronic intestinal inflammation, where HMOX1 activity may play a major role. As part of this article we discuss the immune modulatory capacity of HMOX1 during IBD, as well during the infections and interactions with the microbiota that contribute to this inflammatory disease. © 2018 Sebastián, Salazar, Coronado-Arrázola, Schultz, Vallejos, Berkowitz, álvarez-Lobos, Riedel, Kalergis and Bueno.https://www.frontiersin.org/articles/10.3389/fimmu.2018.01956/ful

One- and many-body effects on mirages in quantum corrals

Recent interesting experiments used scanning tunneling microscopy to study systems involving Kondo impurities in quantum corrals assembled on Cu or noble metal surfaces. The solution of the two-dimensional one-particle Schrodinger equation in a hard wall corral without impurity is useful to predict the conditions under which the Kondo effect can be projected to a remote location (the quantum mirage). To model a soft circular corral, we solve this equation under the potential W*delta(r-r0), where r is the distance to the center of the corral and r0 its radius. We expand the Green's function of electron surface states Gs0 for r<r0 as a discrete sum of contributions from single poles at energies epsilon_i-I*delta_i. The imaginary part delta_i is the half-width of the resonance produced by the soft confining potential, and turns out to be a simple increasing function of epsilon_i. In presence of an impurity, we solve the Anderson model at arbitrary temperatures using the resulting expression for Gs0 and perturbation theory up to second order in the Coulomb repulsion U. We calculate the resulting change in the differential conductance Delta dI/dV as a function of voltage and space, in circular and elliptical corrals, for different conditions, including those corresponding to recent experiments. The main features are reproduced. The role of the direct hybridization between impurity and bulk, the confinement potential, the size of the corral and temperature on the intensity of the mirage are analyzed. We also calculate spin-spin correlation functions.Comment: 13 pages, 12 figures, accepted for publication in Phys. Rev. B. Calculations of spin correlations within an additional approximation adde

The Chilean Strawberry (Fragaria chiloensis): Over 1000 Years of Domestication

Retamales, JB (Retamales, Jorge B.)[ 2 ] ; Lobos, GA (Lobos, Gustavo A.)[ 2 ]. Univ Talca, Fac Ciencias Agr, Ctr Mejoramiento & Fenom Vegetal, Talca, Chile.The cultivated strawberry of South America, the octoploid Fragaria chiloensis, has a long and interesting history. Although the origin of the species in Chile has not been completely determined, it may have been introduced from North America by birds. After making landfall in Chile, the species spread from the coast into the mountains eventually developing four biotypes. At least two native peoples, the Mapuche, between Rio Bio-Bio and south central Chile, and the Picunche, between Rio Itata and Rio Bio-Bio, began the domestication process. Although white- and red-fruited forms were domesticated, the white form (likely because of its fruit size) may have been preferred because the red-fruited types are not mentioned as frequently in the literature. At the time of the Spanish invasion of Chile, F. chiloensis was widely grown in small garden plots. Under the Spanish rule, larger plantings, first of 1 to 2 ha and later of many hectares, were grown. As the Spanish continued their exploration and conquest of South America, they carried F. chiloensis with them up the western coast to Peru and Ecuador. For many years these scattered plantings were the source of fresh fruit for the burgeoning human populations. The cultivated F. x ananassa was introduced in Chile approximate to 1830 but F. chiloensis was still preferentially grown. In the early 1900s, a large canning industry emerged serving hundreds of acres of F. chiloensis. By the 1950s, F. x ananassa began to predominate and the rise in importance of the University of California and European-developed cultivars displaced much of the traditional F. chiloensis production. An increased awareness of this vast native Chilean genetic resource arose in the 1980s and 1990s. Scientists at the Universidad de Talca, associated with USDA-ARS Plant Exploration Office-sponsored trips to Chile, and with El Instituto de Investigaciones Agropecuarias-Cauquenes in Chile have collected and characterized germplasm that represents not only tremendous diversity, but captures many of the land races that have been developed. This germplasm has been used in small commercial plantings (0.1 to 0.3 ha) and in breeding programs to further develop F. chiloensis commercial cultivars. A small but vibrant community of small growers, particularly in Chile and Ecuador, produce the land races for commercial sale in local markets. Approximately 30 to 40 ha of open-field plantings are cultivated in Chile with yields averaging approximate to 3 to 4 tons/ha. The selected F. chiloensis genotypes and collected clones from the wild have served as a valuable source of germplasm in modern breeding programs and the development of new cultivars with the white color and aromatic flavor typical of some of the traditional selections well underway

Efecto de la aplicación de DPA [Difenilamina] y 1-MCP 1-metilciclopropeno] sobre compuestos químicos relacionados con el desarrollo de escaldado superficial de manzanas Granny Smith

Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following treatments: DPA (2,000 ppm); 1-MCP (1.2 ppm) and control (no treatment). All fruit was stored for 4 or 6 months at 0 deg C. A completely randomized factorial design was used (2 harvest dates by 3 postharvest treatments). Monthly measurements were made on maturity indices, ethylene production rate (EPR), scald related compounds (alpha-farnesene (AF), conjugated trienes (CT), total anti-oxidants (AO)), and cell membrane stability. Following 4 and 6 months of storage, plus 7 days at 20 deg C, scald was evaluated. After 6 months, DPA-treated fruit, from both harvests, showed similar firmness, EPR and AO, compared to the control. However, AF and CT were lower, and cell membrane stability higher. Conversely, 1-MCP-treated fruit showed a noticeable EPR suppression and AF inhibition, along with higher firmness, lower CT and AO, compared to the control and DPA. Furthermore, cell membrane stability was superior to that of the control and similar to that of the DPA. Treated fruit (DPA and 1-MCP) showed an important reduction in scald compared to the control. The effect of 1-MCP on the investigated compounds and the reduction in scald, confirms that ethylene plays a major role on its development.Se realizó una investigación para estudiar el modo de acción de difenilamina (DPA) y 1-metilciclopropeno (1-MCP) en el control de escaldado superficial de manzanas (Malus domestica Borkh.) Granny Smith y su relación con compuestos químicos. La fruta fue cosechada de un huerto comercial en Chile, 182 y 189 días después de plena flor y recibió los siguientes tratamientos: DPA (200 ppm), 1-MCP (1,2 ppm) y control (sin tratamiento). Toda la fruta fue almacenada de 4 a 6 meses a 0 grados C. Se utilizó un diseño factorial completamente al azar (2 fechas de cosecha x 3 tratamientos postcosecha). Mensualmente se realizaron mediciones de índices de madurez, tasa de producción de etileno (EPR), compuestos relacionados con el escaldado (alfa-farneseno (AF), trienos conjugados (CT), antioxidantes totales (AO)) y estabilidad de la membrana celular. El escaldado fue evaluado después de 4 y 6 meses de almacenaje, más 7 días a 20 grados C. Después de 6 meses, la fruta tratada con DPA, de ambas cosechas, mostró similar firmeza, EPR y AO en comparación al control. Sin embargo, AF y CT fueron menores y la estabilidad de la membrana celular mayor. Por otra parte, la fruta tratada con 1-MCP mostró una notable supresión de EPR e inhibición de AF, junto a una mayor firmeza, menor CT y AO, en comparación con el control y el tratamiento con DPA. Adicionalmente, la estabilidad de la membrana celular fue superior a la del control y similar a la de DPA. La fruta tratada (DPA y 1-MCP) mostró un desarrollo del escaldado reducido comparado con el control. El efecto de 1-MCP en los compuestos investigados y en la reducción del desorden confirma el papel preponderante del etileno en su desarrollo

Effect of supplementing rumen-protected methionine on production and nitrogen excretion in lactating dairy cows

Two 4 � 4 Latin square trials (4-wk periods; 16 wk total) were conducted to see whether supplementing rumen-protected Met (RPM; fed as Mepron) would allow feeding less crude protein (CP), thereby reducing urinary N excretion, but without losing production. In trial 1, 24 Holsteins were fed 4 diets as total mixed rations containing [dry matter (DM) basis]: 18.6% CP and 0 g of RPM/d; 17.3% CP and 5 g of RPM/d; 16.1% CP and 10 g of RPM/d; or 14.8% CP and 15 g of RPM/d. Dietary CP was reduced by replacing soybean meal with high-moisture shelled corn. All diets contained 21% alfalfa silage, 28% corn silage, 4.5% roasted soybeans, 5.8% soyhulls, 0.6% sodium bicarbonate, 0.5% vitamins and minerals, and 27% neutral detergent fiber. There was no effect of diet on intake, weight gain, or yields of protein, lactose, and solids-not-fat. However, production was greater at 17.3% CP plus RPM and 16.1% CP plus RPM than on the other 2 diets. Apparent N efficiency (milk N:N intake) was greatest on the lowest CP diet containing the most RPM. Linear reductions in milk urea N and urinary N excretion were observed with lower dietary CP. In trial 2, 32 Holsteins were fed 4 diets as total mixed rations, formulated from ingredients used in trial 1 and containing 16.1 or 17.3% CP with 0 or 10 g of RPM/d. On average, cows were calculated to be in negative N balance on all diets because of lower than expected DM intake. There was no effect of RPM supplementation on any production trait. However, higher CP gave small increases in yields of milk, protein, and solids-not-fat and tended to increase DM intake and lactose yield. Apparent N efficiency was greater, and milk urea nitrogen was lower, on 16.1% CP. In trial 1, feeding lower CP diets supplemented with RPM resulted in improved N efficiency and reduced urinary N excretion. However, in trial 2, reducing dietary CP from 17.3 to 16.1% reduced milk secretion, an effect that was not reversed by RPM supplementation at low DM intakes when cows were apparently mobilizing body protein. � American Dairy Science Association, 2008

Spectral irradiance, gas exchange characteristics and leaf traits of Vaccinium corymbosum L. 'Elliott' grown under photo-selective nets

Lobos, GA (Lobos, Gustavo A.)1; Retamales, JB (Retamales, Jorge B.)1; Hancock, JF (Hancock, James F.)2; Fiore, JA (Fiore, James A.)2; Cobo, N (Cobo, Nicolas)1; del Pozo, A (del Pozo, Alejandro)1This study analyzed the light quality and quantity under colored shading nets, together with their effects on physiological and morphological traits for Vaccinium corymbosum L. cv. Elliott. Different spectral ranges and shade intensities (25%, 50% and 75%) were produced using colored netting (black, red and white) along with a control (full sun). These were studied on mature northern highbush blueberry plants in two locations, Michigan-USA and Chillan-Chile. Results indicate that this blueberry variety growing under photo-selective nets acclimates strongly to the light environment and that a reduction of up to 50% in direct light improves overall plant photosynthetic characteristics and leaf traits. Light quality (net colors) had a weaker effect on photosynthetic performance than percentage of photosynthetic active range (%PAR). Large differences in irradiances were observed under nets; red ones reduced the visible spectrum and increased infrared wavelengths, whereas white nets reduced ultra violet radiation. Black nets had almost neutral effects on the whole spectrum. CO(2) assimilation rates, measured under nets in the USA, increased with %PAR, up to 50-60% in both growing seasons. Even though %PAR was significantly associated with stomatal density (r(2) = 0.67), stomatal conductance and xylem water potential showed little relationship with %PAR. Maximum PSII photochemical efficiency (F(v)/F(m)), total leaf chlorophyll content and total Chl/leaf N content ratio were negatively correlated (r(2) = 0.75) with %PAR. Leaf water content was negatively correlated with %PAR in USA (r(2) = 0.84), but not in Chile. Specific leaf area was negatively associated with %PAR (r(2) = 0.62 in USA and 0.55 in Chile). Canopy temperature increased with %PAR (r(2) = 0.72). (C) 2011 Elsevier B.V. All rights reserved