Utilización del isótopo radiacivo Cesio-137 para evaluar la tasa de erosión en una ladera degrada en México

In the Ejido La Gavia, in the municipality of Almoloya de Juárez, State of Mexico, the soils dedicated to maize cultivation and cattle grazing show high levels of erosion. Therefore, it is convenient to estimate the soil erosion rate of crops in the sub-basin with the use of tracers. The hypothesis of this study was that the annual erosion rate (Mg ha-1 y-1) on the degraded slope of the Ejido La Gavia can exceed the maximum permitted limits of erosion for this type of agricultural soils. The objective of this study was to quantify the annual erosion rate in a maize plot and a degraded slope of the Ejido, and to identify the deposit areas of the radioactive isotope Cesium-137 (137Cs). The soil sampling of the degraded slope was made in four transects with ten samples in each one, obtaining a total of 40 soil samples. Five reference sites were included, out of which the 137Cs profile was measured at 50 cm depth. At the reference site, the maximum value found was 6.8 Bq kg-1 at a depth of 10 cm, with 96 % of the 137Cs content observed in the first 20 cm of the soil profile. The inventory of 137Cs on the study slope was between 10.2 and 535.1 Bq m-2, which was lower than that found in the selected reference site of 584.3 Bq m-2. The mass balance model 2 was used, obtaining a soil loss rate with values of - 23.5, - 27.5, - 20.9, and - 22.0 Mg ha-1 y-1. Soil erosion rates in the study four site transects far exceeded the permissible limit of 6.7 Mg ha-1 y-1.En el ejido La Gavia, del municipio de Almoloya de Juá-rez, Estado de México, los suelos dedicados al cultivo del maíz y pastoreo de ganado presentan niveles de ero-sión elevados. Debido a ello, es conveniente estimar la tasa de erosión de los suelos de los cultivos de la sub-cuenca con el uso de trazadores. La hipótesis del estu-dio fue que la tasa de erosión anual (Mg ha-1 año-1) en la ladera degradada del ejido La Gavia puede superar los límites máximos permitidos de erosión para este tipo de suelos agrícolas. El objetivo de estudio es cuantificar la tasa de erosión anual en una parcela de cultivo de maíz y una ladera degradada del ejido en comento e identificar las áreas de depósito del isótopo radioactivo Cesio-137 (137Cs). El muestreo de suelos de la ladera degradada se realizó en cuatro transectos con diez muestras en cada uno, con lo cual se obtuvieron 40 muestras de suelo en total. Cinco sitios de referencia se incluyeron de los cua-les se midió el 137Cs del perfil de 50 cm de profundidad. En el sitio de referencia el valor máximo encontrado fue de 6.8 Bq kg-1 a una profundidad de 10 cm, con 96 % de los contenidos de 137Cs observado en los primeros 20 cm del perfil del suelo. El inventario de 137Cs en la ladera de estudio se encontró entre 10.2 y 535.1 Bq m-2, que fue meno al encontrado en el sitio de referencia seleccionado de 584.3 Bq m-2. Se usó el modelo de balance de masa 2 obteniéndose una tasa de pérdida de suelo con valore

Structural insights into the IgE mediated responses induced by the allergens Hev b 8 and Zea m 12 in their dimeric forms

"Oligomerization of allergens plays an important role in IgE-mediated reactions, as effective crosslinking of IgE-Fc epsilon RI complexes on the cell membrane is dependent on the number of exposed B-cell epitopes in a single allergen molecule or on the occurrence of identical epitopes in a symmetrical arrangement. Few studies have attempted to experimentally demonstrate the connection between allergen dimerization and the ability to trigger allergic reactions. Here we studied plant allergenic profilins rHev b 8 (rubber tree) and rZea m 12 (maize) because they represent an important example of cross-reactivity in the latex-pollen-food syndrome. Both allergens in their monomeric and dimeric states were isolated and characterized by exclusion chromatography and mass spectrometry and were used in immunological in vitro experiments. Their crystal structures were solved, and for Hev b 8 a disulfide-linked homodimer was found. Comparing the structures we established that the longest loop is relevant for recognition by IgE antibodies, whereas the conserved regions are important for cross-reactivity. We produced a novel monoclonal murine IgE (mAb 2F5), specific for rHev b 8, which was useful to provide evidence that profilin dimerization considerably increases the IgE-mediated degranulation in rat basophilic leukemia cells.

Structural basis for redox regulation of cytoplasmic and chloroplastic triosephosphate isomerases from Arabidopsis thaliana

"In plants triosephosphate isomerase (TPI) interconyerts glyceraldehyde 3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP) during glycolysis, gluconeogenesis, and the Calvin-Benson cycle. The nuclear genome of land plants encodes two tpi genes, one gene product is located in the cytoplasm and the other is imported into the chloroplast. Herein we report the crystal structures of the TPIs from the vascular plant Arabidopsis thaliana (AtTPIs) and address their enzymatic modulation by redox agents. Cytoplasmic TPI (cTPI) and chloroplast TPI (pdTPI) share more than 60% amino acid identity and assemble as (beta-alpha)(8) dimers with high structural homology. cTPI and pdTPI harbor two and one accessible thiol groups per monomer respectively. cTPI and pdTPI present a cysteine at an equivalent structural position (C13 and C15 respectively) and cTPI also contains a specific solvent accessible cysteine at residue 218 (cTPI-C218). Site directed mutagenesis of residues pdTPI-C15, cTPI-C13, and cTPI-C218 to serine substantially decreases enzymatic activity, indicating that the structural integrity of these cysteines is necessary for catalysis. AtTPIs exhibit differential responses to oxidative agents, cTPI is susceptible to oxidative agents such as diamide and H2O2, whereas pdTPI is resistant to inhibition. Incubation of AtTPIs with the sulfhydryl conjugating reagents methylmethane thiosulfonate (MMTS) and glutathione inhibits enzymatic activity. However, the concentration necessary to inhibit pdTPI is at least two orders of magnitude higher than the concentration needed to inhibit cTPI. Western-blot analysis indicates that residues cTPI-C13, cTPI-C218, and pdTPI-C15 conjugate with glutathione. In summary, our data indicate that AtTPIs could be redox regulated by the derivatization of specific AtTPI cysteines (cTPI-C13 and pdTPI-C15 and cTPI-C218). Since AtTPIs have evolved by gene duplication, the higher resistance of pdTPI to redox agents may be an adaptive consequence to the redox environment in the chloroplast.

EGUAA 10 years after its creation: towards a guitar tradition?

La historia del Ensamble de Guitarras de la Universidad Autónoma de Aguascalientes (EGUAA) está configurada por una red de estados intencionales que han confluido en esta acción académica a través del tiempo: la creación de la Licenciatura en Música en el año 2009 y su rediseño en 2017, el modelo universitario en la formación de músicos, la creación de la Cátedra Alfonso Moreno en 2010 y los propósitos educativos en la Orquesta Filarmónica de la Universidad Autónoma de Aguascalientes, así como las intencionalidades pedagógicas que cada director activa cuando toma la batuta del ensamble. En este artículo se presentará la exploración que los estudiantes de guitarra –miembros del EGUAA– y su profesora de investigación, realizaron sobre la trayectoria del ensamble para verificar si existen indicios para reconocer una tradición guitarrística en esta comunidad universitaria.The history of the Guitar Ensemble of the Autonomous University of Aguascalientes (EGUAA) is shaped by a series of factors that have converge on this academic action over time: the creation of the Bachelor of Music in 2009 and its redesign in 2017, the university model that trains musicians, the creation of the Alfonso Moreno Chair in 2010, the educational purposes in the Philharmonic Orchestra of the Autonomous University of Aguascalientes, as well as the pedagogical intentions that each director activates when he takes the baton of the ensemble. This article will present the exploration that the guitar students –members of EGUAA– and their research professor, carried out on the ensemble’s trajectory to verify if there are clues to recognize a guitar tradition in this university community.Sociedad Argentina para las Ciencias Cognitivas de la Músic

Substrate-induced dimerization of engineered monomeric variants of triosephosphate isomerase from Trichomonas vaginalis

"The dimeric nature of triosephosphate isomerases (TIMs) is maintained by an extensive surface area interface of more than 1600 angstrom 2. TIMs from Trichomonas vaginalis (TvTIM) are held in their dimeric state by two mechanisms: a ball and socket interaction of residue 45 of one subunit that fits into the hydrophobic pocket of the complementary subunit and by swapping of loop 3 between subunits. TvTIMs differ from other TIMs in their unfolding energetics. In TvTIMs the energy necessary to unfold a monomer is greater than the energy necessary to dissociate the dimer. Herein we found that the character of residue I45 controls the dimer-monomer equilibrium in TvTIMs. Unfolding experiments employing monomeric and dimeric mutants led us to conclude that dimeric TvTIMs unfold following a four state model denaturation process whereas monomeric TvTIMs follow a three state model. In contrast to other monomeric TIMs, monomeric variants of TvTIM1 are stable and unexpectedly one of them (I45A) is only 29-fold less active than wild-type TvTIM1. The high enzymatic activity of monomeric TvTIMs contrast with the marginal catalytic activity of diverse monomeric TIMs variants. The stability of the monomeric variants of TvTIM1 and the use of cross-linking and analytical ultracentrifugation experiments permit us to understand the differences between the catalytic activities of TvTIMs and other marginally active monomeric TIMs. As TvTIMs do not unfold upon dimer dissociation, herein we found that the high enzymatic activity of monomeric TvTIM variants is explained by the formation of catalytic dimeric competent species assisted by substrate binding.

Overexpression of a SDD1-Like Gene From Wild Tomato Decreases Stomatal Density and Enhances Dehydration Avoidance in Arabidopsis and Cultivated Tomato

Stomata are microscopic valves formed by two guard cells flanking a pore, which are located on the epidermis of most aerial plant organs and are used for water and gas exchange between the plant and the atmosphere. The number, size and distribution of stomata are set during development in response to changing environmental conditions, allowing plants to minimize the impact of a stressful environment. In Arabidopsis, STOMATAL DENSITY AND DISTRIBUTION 1 (AtSDD1) negatively regulates stomatal density and optimizes transpiration and water use efficiency (WUE). Despite this, little is known about the function of AtSDD1 orthologs in crop species and their wild stress-tolerant relatives. In this study, SDD1-like from the stress-tolerant wild tomato Solanum chilense (SchSDD1-like) was identified through its close sequence relationship with SDD1-like from Solanum lycopersicum and AtSDD1. Both Solanum SDD1-like transcripts accumulated in high levels in young leaves, suggesting that they play a role in early leaf development. Arabidopsis sdd1-3 plants transformed with SchSDD1-like under a constitutive promoter showed a significant reduction in stomatal leaf density compared with untransformed sdd1-3 plants. Additionally, a leaf dehydration shock test demonstrated that the reduction in stomatal abundance of transgenic plants was sufficient to slow down dehydration. Overexpression of SchSDD1-like in cultivated tomato plants decreased the stomatal index and density of the cotyledons and leaves, and resulted in higher dehydration avoidance. Taken together, these results indicate that SchSDD1-like functions in a similar manner to AtSDD1 and suggest that Arabidopsis and tomatoes share this component of the stomatal development pathway that impinges on water status

Metforminium Decavanadate as a Potential Metallopharmaceutical Drug for the Treatment of Diabetes Mellitus

New potential drugs based on vanadium are being developed as possible treatments for diabetes mellitus (DM) and its complications. In this regard, our working group developed metforminium decavanadate (MetfDeca), a compound with hypoglycemic and hypolipidemic properties. MetfDeca was evaluated in models of type 1 and type 2 diabetes mellitus, on male Wistar rats. Alloxan-induction was employed to produce DM1 model, while a hypercaloric-diet was employed to generate DM2 model. Two-month treatments with 3.7 μg (2.5 μM)/300 g/twice a week for DM2 and 7.18 μg (4.8 μM)/300 g/twice a week for DM1 of MetfDeca, respectively, were administered. The resulting pharmacological data showed nontoxicological effects on liver and kidney. At the same time, MetfDeca showed an improvement of carbohydrates and lipids in tissues and serum. MetfDeca treatment was better than the monotherapies with metformin for DM2 and insulin for DM1. Additionally, MetfDeca showed a protective effect on pancreatic beta cells of DM1 rats, suggesting a possible regeneration of these cells, since they recovered their insulin levels. Therefore, MetfDeca could be considered not only as an insulin-mimetic agent, but also as an insulin-enhancing agent. Efforts to elucidate the mechanism of action of this compound are now in progress

Decavanadate Salts of Cytosine and Metformin: A Combined Experimental-Theoretical Study of Potential Metallodrugs Against Diabetes and Cancer

Cytosine, a DNA and RNA building-block, and Metformin, the most widely prescribed drug for the treatment of Type 2 Diabetes mellitus were made to react separately with ammonium or sodium metavanadates in acidic aqueous solutions to obtain two polyoxovanadate salts with a 6:1 ratio of cation-anion. Thus, compounds [HCyt]6[V10O28]·4H2O, 1 and [HMetf]6[V10O28]·6H2O, 2 (where HCyt = Cytosinium cation, [C4H6N3O]+ and HMetf = Metforminium cation, [C4H12N5]+) were obtained and characterized by elemental analysis, single crystal X-ray diffraction, vibrational spectroscopy (IR and Raman), solution 51V-NMR, thermogravimetric analysis (TGA-DTGA), as well as, theoretical methods. Both compounds crystallized in P1¯ space group with Z' = 1/2, where the anionic charge of the centrosymmetric ion [V10O28]6− is balanced by six Cytosinium and six Metforminium counterions, respectively. Compound 1 is stabilized by π-π stacking interactions coming from the aromatic rings of HCyt cations, as denoted by close contacts of 3.63 Å. On the other hand, guanidinium moieties from the non-planar HMetf in Compound 2 interact with decavanadate μ2-O atoms via N−H···O hydrogen bonds. The vibrational spectroscopic data of both IR and Raman spectra show that the dominant bands in the 1000-450 cm−1 range are due to the symmetric and asymmetric ν(V−O) vibrational modes. In solution, 51V-NMR experiments of both compounds show that polyoxovanadate species are progressively transformed into the monomeric, dimeric and tetrameric oxovanadates. The thermal stability behavior suggests a similar molecular mechanism regarding the loss of water molecules and the decomposition of the organic counterions. Yet, no changes were observed in the TGA range of 540–580°C due to the stability of the [V10O28]6− fragment. Dispersion-corrected density functional theory (DFT-D) calculations were carried out to model the compounds in aqueous phase using a polarized continuum model calculation. Optimized structures were obtained and the main non-covalent interactions were characterized. Biological activities of these compounds are also under investigation. The combination of two therapeutic agents opens up a window toward the generation of potential metalopharmaceuticals with new and exciting pharmacological properties

Validation of UVEDAI: An Index for Evaluating the Level of Inflammatory Activity in Uveitis

Introduction Uveitis is the inflammation of the middle layer of the eye, the uvea, and is a major cause of blindness. None of the instruments used in clinical practice are, in themselves, sufficient to evaluate the course of uveitis. Therefore, it is necessary to develop instruments enabling standardized measurement of inflammatory activity. We developed a composite disease activity index for patients with uveitis known as UVEDAI, which considers the overall activity of the eye. The objective of this study was to validate the composite index of ocular inflammation, UVEDAI. Methods A multicenter cross-sectional study involving eight Spanish tertiary hospitals. Sixty-two patients aged ≥ 18 years with acute uveitis were recruited. Participants gave informed consent before participating in the study. A full ophthalmological examination was performed by two ophthalmologists to determine inflammatory activity: one used the UVEDAI score and the other used clinical judgment. The ophthalmologists did not share their findings with each other to avoid introducing bias into the analysis. Construct validity was established by means of factor analysis. The criterion validity of the index was determined using an ordinal multivariate regression model, in which the dependent variable was the degree of uveal inflammation (mild, moderate, or high/severe). Cut-off points were determined for the UVEDAI and for the receiver operating characteristic (ROC) curves. Results Sixty-two patients were included. Total variance with the three components accounted for 80.32% of the construct validity. Each of the three components identified one type of eye involvement. The discriminatory capacity of UVEDAI was 0.867 (95% CI 0.778; 0.955 p < 0.001) for mild versus moderate–high and 0.946 (95% CI 0.879; 1.000 p < 0.001) for high versus mild–moderate. Conclusions The variables included in UVEDAI enable ocular inflammatory activity to be described with a high degree of accuracy. The index may be used to evaluate and classify this activity with considerable discriminatory power.We would like to acknowledge the support of Abbvie: this study was conducted with an unrestricted grant from Abbvie. The Spanish Society of Rheumatology is the sponser and funder of this study and the journal's Rapid Service Fee, and has participated in the study design; in the analysis, and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication. The corresponding author had full access to all study data and had final responsibility for the decision to submit the manuscript for publication

Common genetic variation in KATNAL1 non-coding regions is involved in the susceptibility to severe phenotypes of male infertility

Free PMC article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9546047/Background: Previous studies in animal models evidenced that genetic mutations of KATNAL1, resulting in dysfunction of its encoded protein, lead to male infertility through disruption of microtubule remodelling and premature germ cell exfoliation. Subsequent studies in humans also suggested a possible role of KATNAL1 single nucleotide polymorphisms in the development of male infertility as a consequence of severe spermatogenic failure. Objectives: The main objective of the present study is to evaluate the effect of the common genetic variation of KATNAL1 in a large and phenotypically well-characterised cohort of infertile men because of severe spermatogenic failure. Materials and methods: A total of 715 infertile men because of severe spermato genic failure, including 210 severe oligospermia and 505 non-obstructive azoospermia patients, as well as 1058 unaffected controls were genotyped for three KATNAL1 single-nucleotide polymorphism taggers (rs2077011, rs7338931 and rs2149971). Case–control association analyses by logistic regression assuming different models and in silico functional characterisation of risk variants were conducted. Results: Genetic associations were observed between the three analysed taggers and different severe spermatogenic failure groups. However, in all cases, the haplotype model (rs2077011*C | rs7338931*T | rs2149971*A) better explained the observed associations than the three risk alleles independently. This haplotype was associated with non-obstructive azoospermia (adjusted p = 4.96E-02, odds ratio = 2.97), Sertoli cell only syndrome (adjusted p = 2.83E-02, odds ratio = 5.16) and testicular sperm extraction unsuccessful outcomes (adjusted p = 8.99E-04, odds ratio = 6.13). The in silico analyses indicated that the effect on severe spermatogenic failure predisposition could be because of an alteration of the KATNAL1 splicing pattern. Conclusions: Specific allelic combinations of KATNAL1 genetic polymorphisms may confer a risk of developing severe male infertility phenotypes by favouring the overrepresentation of a short non-functional transcript isoform in the testis.This work was supported by the Spanish Ministry of Economy and Competitiveness through the Spanish National Plan for Scientific and Technical Research and Innovation (refs. SAF2016-78722-R and PID2020-120157RB-I00), the ‘Instituto de Salud Carlos III’ (Fondo de Investigaciones Sanitarias)/Fondo Europeo de Desarrollo Regional ‘Una manera de hacer Europa’ (FIS/FEDER) (ref. DTS18/00101 to Sara Larriba), the Generalitat de Catalunya (ref. 2017SGR191), the ‘Ramón y Cajal’ program (ref. RYC-2014-16458) and the ‘Juan de la Cierva Incorporación’ program (ref. IJC2018-038026-I), as well as the Andalusian Government through the R&D&i Projects Grants for Universities and Public Research Entities (ref. PY20_00212), which include FEDER funds. Andrea Guzmán-Jiménez was a recipient of a grant from the Spanish Ministry of Education and Professional Training (‘Becas de Colaboración en Departamentos Universitarios para el curso académico 2020/2021’). Patricia I. Marques is supported by the FCT post-doctoral fellowship (SFRH/BPD/120777/2016), financed from the Portuguese State Budget of the Ministry for Science, Tech nology and High Education and from the European Social Fund, available through the ‘Programa Operacional do Capital Humano’. João Gonçalves was partially funded by FCT/MCTES through national funds attributed to the Centre for Toxicogenomics and Human Health— ToxOmics (UID/BIM/00009/2016 and UIDB/00009/2020). Sara Larriba is sponsored by the Researchers Consolidation Program (ISCIII SNS/Dpt. Salut Generalitat de Catalunya) (CES09/020).info:eu-repo/semantics/publishedVersio