Respuesta del perifiton de agua dulce al glifosato grado-técnico y dos formulados comerciales

El glifosato es el herbicida más utilizado a nivel mundial. Puede llegar a los cuerpos de agua y afectar a las comunidades microbianas. Comparamos los efectos del glifosato grado técnico y dos formulados comerciales sobre una comunidad periférica de agua dulce. Se llevó a cabo un experimento de laboratorio con cuatro tratamientos: glifosato ácido grado técnico, Glifosato II Atanor, Roundup Max, a una concentración de 3 mg de ingrediente activo/L, y un Control. A los 2, 5 y 9 días posteriores a la aplicación de los herbicidas se determinaron la concentración de pigmentos, peso seco, peso seco libre de cenizas y densidad algal del perifiton. Se registró un incremento de la abundancia de Cyanobacteria y una disminución de Chlorophyta y Bacillariophyta en todos los tratamientos con herbicida. Este efecto fue mayor con la adición de Roundup Max y Glifosato II Atanor, y fue menor con glifosato grado técnico, sugiriendo que los aditivos en los formulados comerciales pueden intensificar los efectos del glifosatoGlyphosate is the most widely used herbicide worldwide. It may reach water bodies and affect microbial communities. We compared the effects of two commercial formulations and technical-grade glyphosate on a freshwater periphytic community. A laboratory bioassay was carried out with four treatments: technical-grade glyphosate acid, Glifosato II Atanor, Roundup Max, at a concentration of 3 mg active ingredient/L, and Control. At 2, 5 and 9 days after herbicide application, pigments concentration, dry weight, ash-free dry weight, and periphytic algal density were determined. An increase of Cyanobacteria and a decrease of Chlorophyta and Bacillariophyta abundances were registered in all treatments with the herbicide. This effect was greater when Roundup Max and Glifosato II Atanor® were added, and was lower with technical-grade glyphosate, suggesting that additives in the commercial formulations may enhance glyphosate effects.Fil: Gonzalez, Daniela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Juarez, Angela Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Krug, Cecilia Pamela. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santos, Marina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Vera, Maria Solange. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Engineering Two Human Proteins with \u3b2-Trefoil Fold for Therapeutic Applications

The expression of glycoproteins containing immature truncated O-glycans such as the Thomsen-Friedenreich antigen (Ser/Thr-O-Gal\u3b21\u20133GalNAc; T-antigen) and the Lewis antigen (sialyl-T-antigen) is a characteristic feature observed on almost all malignant epithelial cells. Those antigens can be recognized by lectins, a group of highly specific carbohydrate-binding proteins whose three-dimensional structure has been studied in our laboratory by X-ray crystallography. BEL \u3b2-trefoil is a lectin found in mushrooms that contains three binding sites for the T-antigen, its antiproliferative activity was demonstrated in various human tumor cell lines and it has also been employed for the targeting of antitumor drugs. Unlike other lectins with these properties, BEL \u3b2-trefoil presents a structural fold that is also found in human proteins, unlocking the opportunity to use protein engineering tools to design new anticancer therapeutics. This thesis explores the possibility of modifying existing human proteins to recognize the carbohydrate antigens present on the surface of cancer cells, in order to reduce the potential immunogenicity risk that foreign lectins could have and allowing their future application in drug-delivery targeting. To reach this purpose, two human proteins structurally similar to BEL \u3b2-trefoil were modified following different strategies. Human acidic fibroblast growth factor (FGF1) was modified in an attempt to create a new carbohydrate binding site, while a truncated form of human N-acetylgalactosaminyltranferase-6 (GalNAc-T6) was produced to exploit its affinity to N-acetylgalactosamine for this new purpose. Biophysical methods such as spectrofluorimetry and isothermal titration calorimetry were used to analyze the ability of the engineered proteins to bind the T-antigen monosaccharides. The binding dissociation constant (Kd) of the protein-carbohydrate interaction was determined. The stability of each protein was also studied through their thermodynamic parameters of unfolding using differential scanning calorimetry. Crystallization screenings were set up using a broad variety of precipitants in order to produce crystals to be used to study the three-dimensional structure of the engineered proteins using X-ray diffraction. The crystals that were grown were taken to the European Synchrotron Radiation Facility (ESRF) in Grenoble (France) to carry out the diffraction experiments. In conclusion, this work provides a new and interesting insight for the production of optimized protein therapeutics applied in drug-delivery methods for cancer treatment. The present biophysical data are the prerequisite for future studies regarding the biological properties of the engineered proteins and clinical parameters for their potential use in medicine

Primeros registros de características reproductivas de la lagartija patagónica, Liolaemus xanthoviridis (Iguania: Liolaemidae)

Liolaemus is one of the largest radiations of lizards with more than 289 species described. Little is known about the reproductive characteristics and natural history of the majority of these species. Within the L. fitzingerii group, we find L. xanthoviridis is distributed in an area around the Montemayor Plateau in the eastern Atlantic coast of Chubut Province, Argentina. We present the first data on some reproductive traits of this species. Liolaemus xanthoviridis is an oviparous species, that presented a seasonal reproduction (spring-summer) and the clutch size was positively associated with female size, in average the clutch size was eight eggs.Liolaemus presenta es de las mayores radiaciones de lagartijas con más de 289 especies descritas. Se sabe poco sobre las características reproductivas y la historia natural de la mayoría de estas especies. Dentro del grupo L. fitzingerii, encontramos la especie L. xanthoviridis, la cual se distribuye en un área alrededor de la meseta de Montemayor en la costa atlántica oriental de la provincia de Chubut, Argentina. Aquí, presentamos los primeros datos sobre algunos rasgos reproductivos de esta especie. L. xanthoviridis es una especie ovípara, que presentó una reproducción estacional (primavera - verano) y el tamaño de la camada se asoció positivamente con el tamaño de la hembra, en promedio el tamaño de puesta fue de ocho huevosFil: Escudero, Paula Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Gonzalez Marin, Maria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin

Endoparasitic infections in dogs from rural areas in the Lobos District, Buenos Aires province, Argentina

Dogs are definite hosts for several zoonotic helminthes and protozoan. Rural areas from the Lobos District in the northeast of Buenos Aires province, Argentina, are mainly used for livestock activity, increasing in this way the number of dogs on farms as well as the human risk of parasitic infections. The aims of this research were to evaluate the endoparasitic infections in dogs from farms in the Lobos District and analyze their zoonotic importance as well as several risk practices and habits of the rural population. Forty-two dog fecal samples obtained in 21 farms were analyzed through coproparasitological methods and coproantigen tests, which resulted in an overall parasite prevalence of 69.05% and 80.95% of the parasitized farms. The most frequent parasites were Trichuris vulpis and Eucoleus aerophila (26.19%), Echinococcus granulosus (19.05%), Uncinaria stenocephala and coccids (14.29%). The analysis of epidemiological files showed several habits of the rural population considered as risk factors associated with the presence of fecal samples parasitized and the presence of E. granulosus on the farms. It is clear that people involved with the farms studied were exposed to several helminthes that could cause serious diseases like cystic echinococcosis, which can become an important public health issue and affect the economy worldwideOs cães são hospedeiros definitivos de vários helmintos e protozoários zoonóticos. As áreas rurais do distrito de Lobos, no nordeste da província de Buenos Aires, Argentina, destinam-se principalmente à atividade pecuária aumentando desta forma o número de cães em fazendas, bem como o risco humano de infecções parasitárias. Os objetivos desta pesquisa foram avaliar as infecções endoparasitas em cães de fazendas do distrito de Lobos e analisar a sua importância zoonótica, bem como as práticas de risco e hábitos da população rural. Quarenta e duas amostras de fezes de cães obtidos em 21 fazendas foram analisadas pelos métodos coproparasitológicos e testes de coproantígenos, resultando numa prevalência de parasitas de 69,05% e 80,95% das propriedades parasitados. Os parasitas mais frequentes foram Trichuris vulpis e Eucoleus aerophila (26,19%), Echinococcus granulosus (19,05%), Uncinaria stenocephala e coccídeos (14,29%). A análise dos arquivos epidemiológicos mostraram vários hábitos da população rural como fatores de risco associados com a presença de amostras fecais parasitadas e a presença de E. granulosus em propriedades rurais. É evidente que as pessoas das fazendas estudadas foram expostas a vários helmintos que podem causar doenças graves como equinococose cística, que constitui importante problema de saúde pública e econômico a nível mundial.Fil: Dopchiz, Marcela Cecilia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lavallén, Carla Mariela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bongiovanni, Roberto Antonio. Municipalidad de Lobos. Departamento de Bromatología y Zoonosis. Lobos; ArgentinaFil: Gonzalez, Patricia Verónica. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Elissondo, María Celina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Yannarella, Francisco. Universidad Nacional de La Plata; ArgentinaFil: Denegri, Guillermo Maria. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Triacylglycerol synthesis directed by glycerol-3-phosphate acyltransferases −3 and −4 is required for lipid droplet formation and the modulation of the inflammatory response during macrophage to foam cell transition

Background and aims: The transition of macrophage to foam cells is a major hallmark of early stage atherosclerotic lesions. This process is characterized by the accumulation of large cytoplasmic lipid droplets containing large quantities of cholesterol esters (CE), triacylglycerol (TAG) and phospholipid (PL). Although cholesterol and CE metabolism during foam cell formation has been broadly studied, little is known about the role of the glycerolipids (TAG and PL) in this context. Here we studied the contribution of glycerolipid synthesis to lipid accumulation, focusing specifically on the first and rate-limiting enzyme of the pathway: glycerol-3-phosphate acyltransferase (GPAT). Methods: We used RAW 264.7 cells and bone marrow derived macrophages (BMDM) treated with oxidized LDL (oxLDL). Results: We showed that TAG synthesis is induced during the macrophage to foam cell transition. The expression and activity of GPAT3 and GPAT4 also increased during this process, and these two isoforms were required for the accumulation of cell TAG and PL. Compared to cells from wildtype mice after macrophage to foam cell transition, Gpat4−/− BMDM released more pro-inflammatory cytokines and chemokines, suggesting that the activity of GPAT4 could be associated with a decrease in the inflammatory response, probably by sequestering signaling precursors into lipid droplets. Conclusions: Our results provide evidence that TAG synthesis directed by GPAT3 and GPAT4 is required for lipid droplet formation and the modulation of the inflammatory response during the macrophage-foam cell transition.Fil: Quiroga, Ivana Yoseli. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Pellon Maison, Magali. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Gonzalez, Marina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Coleman, Rosalind A.. University of North Carolina; Estados UnidosFil: Gonzalez Baro, Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; Argentin

Mapping of the self-interaction domains in the simian immunodeficiency virus gag polyprotein

To gain a better understanding of the assembly process in simian immunodeficiency virus (SIV), we first established the conditions under which recombinant SIV Gag lacking the C-terminal p6 domain (SIV GagDp6) assembled in vitro into spherical particles. Based on the full multimerization capacity of SIV GagDp6, and to identify the Gag sequences involved in homotypic interactions, we next developed a pull-down assay in which a panel of histidine-tagged SIV Gag truncation mutants was tested for its ability to associate in vitro with GSTSIVGagDp6. Removal of the nucleocapsid (NC) domain from Gag impaired its ability to interact with GSTSIVGagDp6. However, this Gag mutant consisting of the matrix (MA) and capsid (CA) domains still retained 50% of the wild-type binding activity. Truncation of SIV Gag from its N-terminus yielded markedly different results. The Gag region consisting of the CA and NC was significantly more efficient than wild-type Gag at interacting in vitro with GST-SIVGagDp6. Notably, a small Gag subdomain containing the C-terminal third of the CA and the entire NC not only bound to GST-SIVGagDp6 in vitro at wild-type levels, but also associated in vivo with full-length Gag and was recruited into extracellular particles. Interestingly, when the mature Gag products were analyzed, the MA and NC interacted with GST-SIVGagDp6 with efficiencies representing 20% and 40%, respectively, of the wild-type value, whereas the CA failed to bind to GST-SIVGagDp6, despite being capable of self-associating into multimeric complexes.Fil: Rauddi, Maria Luisa. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mac Donald, Cecilia L.. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología; ArgentinaFil: Affranchino, Jose Luis. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez, Silvia Adriana. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

An Examination of Qualitative Empirical Studies at the AHRD from 1999-2003: Method, Rationale for Method, Data Collection, Sampling Strategies, and Integrity Measures

The paper examines the nature of qualitative empirical studies published in the AHRD proceedings from 1999-2003 and discusses findings on method, rationale for method, data collection, sampling strategies, and integrity measures

Epigenetic control of EMT/MET dynamics: HNF4α impacts DNMT3s through miRs-29

Background and aims: Epithelial-to-mesenchymal transition (EMT) and the reverse mesenchymal-to-epithelial transition (MET) are manifestations of cellular plasticity that imply a dynamic and profound gene expression reprogramming. While a major epigenetic code controlling the coordinated regulation of a whole transcriptional profile is guaranteed by DNA methylation, DNA methyltransferase (DNMT) activities in EMT/MET dynamics are still largely unexplored. Here, we investigated the molecular mechanisms directly linking HNF4α, the master effector of MET, to the regulation of both de novo of DNMT 3A and 3B. Methods: Correlation among EMT/MET markers, microRNA29 and DNMT3s expression was evaluated by RT-qPCR, Western blotting and immunocytochemical analysis. Functional roles of microRNAs and DNMT3s were tested by anti-miRs, microRNA precursors and chemical inhibitors. ChIP was utilized for investigating HNF4α DNA binding activity. Results: HNF4α silencing was sufficient to induce positive modulation of DNMT3B, in in vitro differentiated hepatocytes as well as in vivo hepatocyte-specific Hnf4α knockout mice, and DNMT3A, in vitro, but not DNMT1. In exploring the molecular mechanisms underlying these observations, evidence have been gathered for (i) the inverse correlation between DNMT3 levels and the expression of their regulators miR-29a and miR- 29b and (ii) the role of HNF4α as a direct regulator of miR-29a-b transcription. Notably, during TGFβ-induced EMT, DNMT3s' pivotal function has been proved, thus suggesting the need for the repression of these DNMTs in the maintenance of a differentiated phenotype. Conclusions: HNF4α maintains hepatocyte identity by regulating miR-29a and -29b expression, which in turn control epigenetic modifications by limiting DNMT3A and DNMT3B levels