34 research outputs found
SELECCIÓN DE SONIDOS PARA UN CURSO DE INMERSIÓN DE ESPAÑOL COMO LENGUA SEGUNDA Y EXTRANJERA (ELSE) PARA ANGLOPARLANTES: caso de aplicación en el programa de español para extranjeros de la Universidad Nacional de Mar del Plata, Buenos Aires, Argentina.
Aquest article té tres objectius: proposar una metodologia per a la selecció dels sons de l’espanyol com a llengua segona i estrangera (ELSE) per a ensenyar en un curs d’immersió, presentar una anà lisi contrastiva dels sons vocà lics i consonà ntics de l’espanyol del Riu de la Plata (ERP) i de l’anglès americà general (AAG), i elaborar un inventari dels sons de l’ERP que haurien de ser tractats en una classe d’ELSE.This article has three objectives: to propose a methodology for the selection of L2/LE Spanish sounds to be taught at an immersion course, to present a contrastive analysis of both River Plate Spanish (RPS) and General American English (GAE) vowel and consonant sounds, and to present an inventory of the RPS sounds that should receive treatment in an L2/LE Spanish class.Este artÃculo tiene tres objetivos: proponer una metodologÃa para la selección de los sonidos del español como lengua segunda y extranjera (ELSE) a enseñar en un curso de inmersión, presentar un análisis contrastivo de los sonidos vocálicos y consonánticos del español rioplatense (ERP) y del inglés americano general (IAG), y elaborar un inventario de los sonidos del ERP que deberÃan ser tratados en una clase de ELSE
The Effect of Anandamide on Uterine Nitric Oxide Synthase Activity Depends on the Presence of the Blastocyst
Nitric oxide production, catalyzed by nitric oxide synthase (NOS), should be strictly regulated to allow embryo implantation. Thus, our first aim was to study NOS activity during peri-implantation in the rat uterus. Day 6 inter-implantation sites showed lower NOS activity (0.19±0.01 pmoles L-citrulline mg prot−1 h−1) compared to days 4 (0.34±0.03) and 5 (0.35±0.02) of pregnancy and to day 6 implantation sites (0.33±0.01). This regulation was not observed in pseudopregnancy. Both dormant and active blastocysts maintained NOS activity at similar levels. Anandamide (AEA), an endocannabinoid, binds to cannabinoid receptors type 1 (CB1) and type 2 (CB2), and high concentrations are toxic for implantation and embryo development. Previously, we observed that AEA synthesis presents an inverted pattern compared to NOS activity described here. We adopted a pharmacological approach using AEA, URB-597 (a selective inhibitor of fatty acid amide hydrolase, the enzyme that degrades AEA) and receptor selective antagonists to investigate the effect of AEA on uterine NOS activity in vitro in rat models of implantation. While AEA (0.70±0.02 vs 0.40±0.04) and URB-597 (1.08±0.09 vs 0.83±0.06) inhibited NOS activity in the absence of a blastocyst (pseudopregnancy) through CB2 receptors, AEA did not modulate NOS on day 5 pregnant uterus. Once implantation begins, URB-597 decreased NOS activity on day 6 implantation sites via CB1 receptors (0.25±0.04 vs 0.40±0.05). While a CB1 antagonist augmented NOS activity on day 6 inter-implantation sites (0.17±0.02 vs 0.27±0.02), a CB2 antagonist decreased it (0.17±0.02 vs 0.12±0.01). Finally, we described the expression and localization of cannabinoid receptors during implantation. In conclusion, AEA levels close to and at implantation sites seems to modulate NOS activity and thus nitric oxide production, fundamental for implantation, via cannabinoid receptors. This modulation depends on the presence of the blastocyst. These data establish cannabinoid receptors as an interesting target for the treatment of implantation deficiencies
Selección de sonidos para in curso de inmersión de español como lengua segunda y extranjera (ELSE) para angloparlantes: caso de aplicación en el programa de español para extranjeros de la Universidad Nacional de Mar del Plata, Buenos Aires, Argentina
Aquest article té tres objectius: proposar una metodologia per a la selecció dels sons de l’espanyol com a llengua segona i estrangera (ELSE) per a ensenyar en un curs d’immersió, presentar una anà lisi contrastiva dels sons vocà lics i consonà ntics de l’espanyol del Riu de la Plata (ERP) i de l’anglès americà general (AAG), i elaborar un inventari dels sons de l’ERP que haurien de ser tractats en una classe d’ELSE
Interaction between lysophosphatidic acid, prostaglandins and the endocannabinoid system during the window of implantation in the rat uterus.
Bioactive lipid molecules as lysophosphatidic acid (LPA), prostaglandins (PG) and endocannabinoids are important mediators of embryo implantation. Based on previous published data we became interested in studying the interaction between these three groups of lipid derivatives in the rat uterus during the window of implantation. Thus, we adopted a pharmacological approach in vitro using LPA, DGPP (a selective antagonist of LPA3, an LPA receptor), endocannabinoids' receptor selective antagonists (AM251 and AM630) and non selective (indomethacin) and selective (NS-398) inhibitors of cyclooxygenase-1 and 2 enzymes. Cyclooxygenase isoforms participate in prostaglandins' synthesis. The incubation of the uterus from rats pregnant on day 5 of gestation (implantation window) with LPA augmented the activity and the expression of fatty acid amide hydrolase, the main enzyme involved in the degradation of endocannabinoids in the rodent uteri, suggesting that LPA decreased endocannabinoids' levels during embryo implantation. It has been reported that high endocannabinoids are deleterious for implantation. Also, LPA increased PGE2 production and cyclooxygenase-2 expression. The incubation of LPA with indomethacin or NS-398 reversed the increment in PGE2 production, suggesting that cyclooxygenase-2 was the isoform involved in LPA effect. PGs are important mediators of decidualization and vascularization at the implantation sites. All these effects were mediated by LPA3, as the incubation with DGPP completely reversed LPA stimulatory actions. Besides, we also observed that endocannabinoids mediated the stimulatory effect of LPA on cyclooxygenase-2 derived PGE2 production, as the incubation of LPA with AM251 or AM630 completely reversed LPA effect. Also, LPA augmented via LPA3 decidualization and vascularization markers. Overall, the results presented here demonstrate the participation of LPA3 in the process of implantation through the interaction with other groups of lipid molecules, prostaglandins and endocannabinoids, which prepare the uterine milieu for embryo invasion during the window of implantation
Endogenous lysophosphatidic acid participates in vascularisation and decidualisation at the maternal-fetal interface in the rat. The fundamental role of LPA3 receptor in decidualization and vascularization
Lysophosphatidic acid (LPA) affects several female reproductive functions through G-protein-coupled receptors. LPA contributes to embryo implantation via the lysophospholipid LPA3 receptor. In the present study we investigated the participation of endogenous LPA signalling through the LPA3 receptor in vascularisation and decidualisation, two crucial events at the maternal?fetal interface. Pregnant rats were treated with diacylglycerol pyrophosphate (DGPP), a highly selective antagonist of LPA3 receptors, on Day 5 of gestation. Pregnant rats received intrauterine (i.u.) injections of single doses of DGPP (0.1 mg kg1) in a total volume of 2 mL in the left horn (treated horn) in the morning of GD5. DGPP treatment produced aberrant embryo spacing and increased embryo resorption. The LPA3 receptor antagonist decreased the cross-sectional length of the uterine and arcuate arteries and induced histological anomalies in the decidua and placentas. Marked haemorrhagic processes, infiltration of immune cells and tissue disorganisation were observed in decidual and placental tissues from sites of resorption. The mRNA expression of three vascularisation markers, namely interleukin 10 (Il10), vascular endothelial growth factor (Vegfa) and vascular endothelial growth factor receptor 1 (Vegfr1), was reduced at sites of resorption from Day 8. The results show that the disruption of endogenous LPA signalling by blocking the LPA3 receptor modified the development of uterine vessels with consequences in the formation of the decidua and placenta and in the growth of embryos.Fil: Sordelli, Micaela Soledad. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Beltrame, Jimena Soledad. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Zotta, Elsa. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Departamento de Ciencias Biológicas; ArgentinaFil: Gomez, Natalia. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Departamento de FarmacologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Dmytrenko, Ganna. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Sales, MarÃa Elena. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Blois, Sandra M.. University Medicine of Berlin; AlemaniaFil: Davio, Carlos Alberto. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Departamento de FarmacologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Perez Martinez, Silvina Laura. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Franchi, Ana Maria. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Ribeiro, Maria Laura. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin
Interaction between Lysophosphatidic Acid, Prostaglandins and the Endocannabinoid System during the Window of Implantation in the Rat Uterus
The role of anandamide during pregnancy : A short tale about the endocannabinoid system
The success of any species depends on its reproductive efficiency. Sexual procreation is initiated by interactions between a sperm and an egg leading to fertilization. The fertilized egg (embryo) undergoes several mitotic cell divisions, ultimately producing the blastocyst. The nurturing of an offspring within the body and production of a live birth is an enduring task, requiring safeguard regulatory systems at various critical steps. At the moment, there is still a significant knowledge gap in understanding the mechanisms by which a successful pregnancy is achieved. It is difficult to define the hierarchical landscape of the molecular pathways during human pregnancy, because of experimental difficulties and ethical restrictions on research with human embryos. It is hoped that experiments on mice and other animal models that bear certain reproductive similarities with humans combined with those feasible experiments in humans would generate meaningful information to address this critical issue. A deeper insight into these processes will help to generate new ideas and concepts for improving fertility and pregnancy-associated health issues in humans. During the last years, several studies have provided evidence that lipid mediators are important signaling molecules in coordinating a series of events during pregnancy. Increasing evidence points toward the pathophysiological significance of endocannabinoids, a group of bioactive lipid-signaling molecules, in both female and male fertility.Sociedad Argentina de FisiologÃ
Expression of cannabinoid receptor type-1 at implantation and pseudopregnancy.
<p>Cannabinoid receptor type-1 (CB1) messenger (A and C) and protein (B and D) were detected during peri-implantation (A and B) and on day 5 of pseudopregnancy (C and D). Results are shown as means ± S.E.M. N = 4–6 for each point. a: p<0.001 vs the rest. d4: day 4, d5: day 5, d6: day 6, IM: implantation sites, II: inter-implantation sites, psp: pseudopregnancy.</p
NOS activity in the rat uterus during peri-implantation.
<p>NOS activity was determined (A) on days 4 (d4), 5 (d5) and 6 of gestation (implantation (d6IM) and inter-implantation sites (d6II) were assessed separately on day 6 of pregnancy), (B) in the delayed implantation model and (C) during pseudopregnancy (psp). NOS activity is expressed as pmoles citrulline mg prot<sup>−1</sup> h<sup>−1</sup>. a: p<0,001 vs the rest. N = 4–6 for each point. d4: day 4, d5: day 5, d6: day 6, IM: implantation sites, II: inter-implantation sites.</p