278 research outputs found
Antispasmodic effects and action mechanism of essential oil of Chrysactinia mexicana A. Gray on rabbit ileum
The Chrysactinia mexicana A. Gray (C. mexicana) plant is used in folk medicine to treat fever and rheumatism; it is used as a diuretic, antispasmodic; and it is used for its aphrodisiac properties. This study investigates the effects of the essential oil of C. mexicana (EOCM) on the contractility of rabbit ileum and the mechanisms of action involved. Muscle contractility studies in vitro in an organ bath to evaluate the response to EOCM were performed in the rabbit ileum. EOCM (1–100 µg·mL-1) reduced the amplitude and area under the curve of spontaneous contractions of the ileum. The contractions induced by carbachol 1 µM, potassium chloride (KCl) 60 mM or Bay K8644 1 µM were reduced by EOCM (30 µg·mL-1). Apamin 1 µM and charybdotoxin 0.01 µM decreased the inhibition induced by EOCM. The d-cAMP 1 µM decreased the inhibition induced by EOCM. l-NNA 10 µM, Rp-8-Br-PET-cGMPS 1 µM, d, l-propargylglycine 2 mM, or aminooxyacetic acid hemihydrochloride 2 mM did not modify the EOCM effect. In conclusion, EOCM induces an antispasmodic effect and could be used in the treatment of intestinal spasms or diarrhea processes. This effect would be mediated by Ca2+, Ca2+-activated K+ channels and cAMP
Regulation and role of the PP2A-B56 holoenzyme family in cancer
Protein phosphatase 2A (PP2A) inactivation is common in cancer, leading to sustained activation of pro-survival
and growth-promoting pathways. PP2A consists of a scaffolding A-subunit, a catalytic C-subunit, and a regulatory B-subunit. The functional complexity of PP2A holoenzymes arises mainly through the vast repertoire of
regulatory B-subunits, which determine both their substrate specificity and their subcellular localization.
Therefore, a major challenge for developing more effective therapeutic strategies for cancer is to identify the
specific PP2A complexes to be targeted. Of note, the development of small molecules specifically directed at
PP2A-B56α has opened new therapeutic avenues in both solid and hematological tumors. Here, we focus on the
B56/PR61 family of PP2A regulatory subunits, which have a central role in directing PP2A tumor suppressor
activity. We provide an overview of the mechanisms controlling the formation and regulation of these complexes,
the pathways they control, and the mechanisms underlying their deregulation in cancer
Gender gap in STEM: a cross-sectional study of primary school students’ self-perception and test anxiety in mathematics
Contribution: Significant gender differences are observed on primary school students’ perception of self-efficacy and test anxiety in mathematics. Girls perceive themselves to be significantly worse than boys in mathematics and report higher test anxiety toward mathematics exams. Gender differences in self-efficacy become more pronounced as students grow up, and test anxiety increases for all students. However, the present study shows that teachers’ do not perceive differences in self-efficacy in mathematics between boys and girls. Background: The low presence of women in science, technology, engineering, and mathematics (STEM) might be explained by the attitude of young students toward mathematics. Different studies show that girls are less interested in STEM areas than boys during secondary school. A study on the reasons for this fact pointed out that the early years of education can provide a relevant insight to reverse the situation. Research Questions: Is there any age-dependent gender difference in primary school students in aspects related to mathematics? Are teachers aware of students’ perceptions? Methodology: This work presents a study of over 2000 primary school students (6–12 years old) and 200 teachers in Aragón (Spain). The study consists of a survey on aspects that influence the experience of female and male students with mathematics and Spanish language for comparison purposes and teacher’s awareness of students’ perception. Findings: The present study shows that during primary school, girls are more likely to experiment a negative attitude toward mathematics than boys as they grow up, and teachers may not perceive girls’ situation. La baja presencia de mujeres en ciencia, tecnología, la ingeniería y las matemáticas (STEM) podrían explicarse por la actitud de las niños y niñas hacia las matemáticas. Diferentes estudios muestran que las niñas están menos interesadas en las áreas STEM que niños cuando cursan educación secundaria. Además, un estudio sobre los motivos para este hecho señaló que los primeros años de educación podrían proporcionar una visión relevante para revertir la situación. Por ello, este trabajo parte de las siguientes preguntas de investigación, ¿Existe alguna diferencia de género que sea dependiente de la edad en estudiantes de educación primaria en aspectos relacionados con las matemáticas? ¿Conoce el profesorado la autopercepción de sus estudiantes? Las principales contribuciones de este trabajo son que las diferencias significativas de género se observan en la percepción de autoeficacia de los estudiantes de primaria y ansiedad ante los exámenes en matemáticas. Las niñas se perciben a sí mismas significativamente peor que los niños en matemáticas e indican mayor ansiedad ante los exámenes de matemáticas. Las diferencias de género en la autoeficacia se vuelven más pronunciada a medida que los estudiantes crecen, mientras que la ansiedad ante los exámenes aumenta para todos los estudiantes. Pese a estos resultados, el presente estudio muestra que los profesores no perciben diferencias en la autoeficacia en matemáticas entre niños y niñas. Este estudio se basa en las encuestas realizadas a más de 2000 escolares (6-12 años) y 200 profesores en Aragón (España). El estudio consiste en una encuesta a los estudiantes sobre aspectos que pueden influir en la experiencia de los niños y niñas con las matemáticas, así como con la lengua española para disponer de una materia que permita establecer comparaciones y una encuesta al profesor que incluye cuestiones sobre su percepción de los estudiantes. El principal hallazgo del estudio es que, durante la escuela primaria, es más probable que las niñas experimenten una actitud negativa hacia matemáticas que los niños a medida que crecen, y que los maestros pueden no ser conscientes de la situación de las niñas
Structural and functional findings in patients with moderate diabetic retinopathy
Purpose: To evaluate structural and functional ocular changes in patients with type 2 diabetes mellitus (DM2) and moderate diabetic retinopathy (DR) without apparent diabetic macular edema (DME) assessed by optical coherence tomography (OCT) and microperimetry. Methods: This was a single-center cross-sectional descriptive study for which 75 healthy controls and 48 DM2 patients with moderate DR were included after applying exclusion criteria (one eye per patient was included). All eyes underwent a complete ophthalmic examination (axial length, macular imaging with swept-source OCT, and MAIA microperimetry). Macular thicknesses, ganglion cell complex (GCC) thicknesses, and central retinal sensitivity were compared between groups, and the relationships between the OCT and microperimetry parameters were evaluated. Results: Macular thickness was similar in both groups (242.17 ± 35.0 in the DM2 group vs 260.64 ± 73.9 in the control group). There was a diminution in the parafoveal area thickness in the DM2 group in the GCC complex. Retinal sensitivity was reduced in all sectors in the DM2 group. The central global value was 24.01 ± 5.7 in the DM2 group and 27.31 ± 2.7 in the control group (p < 0.001). Macular integrity was 80.89 ± 26.4 vs 64.70 ± 28.3 (p < 0.001) and total mean threshold was 23.90 ± 4.9 vs 26.48 ± 2.6 (p < 0.001) in the DM2 and control group, respectively. Moderate correlations were detected between the central sector of MAIA microperimetry and retina total central thickness (- 0.347; p = 0.0035). Age, visual acuity, and hemoglobin A1c levels also correlated with retinal sensitivity. Conclusion: Macular GCC thickness and central retinal sensitivity were reduced in patients with moderate DR without DME, suggesting the presence of macular neurodegeneration.[Figure not available: see fulltext.] © 2021, The Author(s)
Estado de estrés oxidativo en el hígado graso experimental en ratones machos y su proyección sobre la funcionalidad hepática
En medicina veterinaria, el rol del estrés oxidativo (EO) en la producción y reproducción animal ha adquirido relevancia debido al deterioro de ambas funciones en animales con hepatoesteatosis o hígado graso (HG). Este estudio tuvo el objetivo de determinar si en el HG experimental causado por etionina en ratones machos NMRI adultos, se establecía un estado de EO hepático y se alteraba la función del hígado. Se utilizaron dos grupos de 10 animales: uno control y otro tratado con DL-etionina por vía intraperitoneal en dosis de 7,5 mg/20 g de peso corporal. La magnitud y características del HG fueron determinadas histológicamente y la cuantía del depósito graso hepático se estableció por la concentración de triglicéridos, análisis que corroboraron la generación de hepatoesteatosis en los machos inyectados con DL-etionina. Los productos de la degradación lipoperoxidativa, dienos conjugados (DC) y malondialdehído (MDA), indicadores de EO celular, fueron cuantificados por espectrofotometría, mediante su concentración en el homogeneizado hepático. El daño en la funcionalidad hepática se cuantificó por los niveles plasmáticos de la alanina aminotransferasa (ALT) y de la aspartato aminotransferasa (AST), mediante kits comerciales. La inducción de HG causó una elevación significativa de los DC: de 231,18 ± 15,53 µmoles/mg proteínas a 297,45 ± 23,10 mmoles/mg proteínas (P<0,05), así como del MDA: de 364,91 ± 17,73 nmoles/mg proteínas a 852,91 ± 55,26 nmoles/mg proteínas (P<0,001). En los ratones con HG, la actividad plasmática de las aminotransferasas aumentó significativamente: ALT de 59,40 ± 5,16 U/l a 169,86 ± 18,78 U/l (P<0,001) y AST de 158,35 ± 13,54 U/l a 241,93 ± 10,14 U/l (P<0,05). Estos resultados muestran que en el HG inducido por etionina en ratones machos NMRI se produce un estado de EO que podría ser responsable de la alteración en la funcionalidad hepática.
In veterinary medicine the role of oxidative stress (OS) in animal production and reproduction has become important due to the alteration of both functions in animals with hepatosteatosis or fatty liver (FL). This study aimed to determine whether a state of hepatic OS was established in the experimental FL caused by ethionine in adult male mice NMRI, and whether liver function was altered. Two groups of 10 animals were used: one control and another treated with DL-ethionine intraperitoneally at 7.5 mg/20 g body weight. The magnitude and characteristics of FL were determined histologically and the amount of liver fat depot was established by the concentration of triglycerides. Both analysis corroborated generation of hepatosteatosis in males injected with DL-ethionine. Products from lipoperoxidative degradation (conjugated dienes (CD) and malondialdehyde (MDA), indicators of cellular OS, were quantified spectrophotometrically by its concentration in liver homogenate. Damage to liver function was measured by plasmatic levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), using commercial kits. The induction of FL caused a significant rise in CD from 231.18 ± 15.53 µmoles/mg protein to 297.45 ± 23.10 mmoles/mg protein (P<0.05), as well as the MDA: from 364.91 ± 17.73 nmoles/mg protein to 852.91 ± 55.26 nmoles/mg protein (P<0.001). In mice with FL aminotransferases plasmatic activity increased significantly: ALT of 59.40 ± 5.16 U/l from 169.86 ± 18.78 U/l (P<0.001) and AST from 158.35 ± 13.54 U/l to 241.93 ± 10.14 U/l (P<0.05). These results show that in ethionine-induced FL in male NMRI mice a state of OS is induced that could be responsible for the alteration in liver function
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS
The chi_b(nP) quarkonium states are produced in proton-proton collisions at
the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS
detector. Using a data sample corresponding to an integrated luminosity of 4.4
fb^-1, these states are reconstructed through their radiative decays to
Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks
corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new
structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is
also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes.
This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table,
corrected author list, matches final version in Physical Review Letter
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
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