Dimensión Cromosómica Honfi, Ana Isabel; Bolzan, Alejandro Daniel; Daviña, Julio Rubén Desde la segunda década del siglo pasado, Argentina ha sido el epicentro del inicio y desarrollo de la citogenética en América latina. La citogenética es una disciplina que se caracteriza por su capacidad de constante rejuvenecimiento y resurgimiento, aún después de etapas de franca declinación de su manejo y aplicación. Los rasgos cromosómicos son cualidades determinísticas de gran valor predictivo y su estudio aunque requiere de cierta práctica artesanal, resulta una herramienta fundamental para acompañar tecnologías de vanguardia, como una herramienta poderosa, versátil y fundamentalmente insustituible por otros abordajes. En este artículo, trataremos algunas facetas de la dimensión cromosómica del análisis genético de diversos grupos de organismos.

Single nucleotide polymorphisms may explain the contrasting phenotypes of two variants of a multidrug-resistant Mycobacterium tuberculosis strain Bigi, Maria de Las Mercedes; Lopez, Beatriz; Blanco, Federico Carlos; Sasiain, María del Carmen; de la Barrera, Silvia Susana; Marti, Marcelo Adrian; Sosa, Ezequiel; Fernández Do Porto, Darío Augusto; Ritacco, Gloria Viviana; Bigi, Fabiana; Soria, Marcelo Abel Globally, about 4.5% of new tuberculosis (TB) cases are multi-drug-resistant (MDR), i.e. resistant to the two most powerful first-line anti-TB drugs. Indeed, 480,000 people developed MDR-TB in 2015 and 190,000 people died because of MDR-TB. The MDR Mycobacterium tuberculosis M family, which belongs to the Haarlem lineage, is highly prosperous in Argentina and capable of building up further drug resistance without impairing its ability to spread. In this study, we sequenced the whole genomes of a highly prosperous M-family strain (Mp) and its contemporary variant, strain 410, which produced only one recorded tuberculosis case in the last two decades. Previous reports have demonstrated that Mp induced dysfunctional CD8+ cytotoxic T cell activity, suggesting that this strain has the ability to evade the immune response against M. tuberculosis. Comparative analysis of Mp and 410 genomes revealed non-synonymous polymorphisms in eleven genes and five intergenic regions with polymorphisms between both strains. Some of these genes and promoter regions are involved in the metabolism of cell wall components, others in drug resistance and a SNP in Rv1861, a gene encoding a putative transglycosylase that produces a truncated protein in Mp. The mutation in Rv3787c, a putative S-adenosyl-L-methionine-dependent methyltransferase, is conserved in all of the other prosperous M strains here analysed and absent in non-prosperous M strains. Remarkably, three polymorphic promoter regions displayed differential transcriptional activity between Mp and 410. We speculate that the observed mutations/polymorphisms are associated with the reported higher capacity of Mp for modulating the host's immune response.

Carbon nanotubes grown on carbon fiber yarns by a low temperature CVD method: A significant enhancement of the interfacial adhesion between carbon fiber/epoxy matrix hierarchical composites Vozer Felisberto, Marcos Daniel; Tzounis, Lazaros; Sacco, Leandro; Stamm, Manfred; Candal, Roberto Jorge; Rubiolo, Gerardo Hector; Goyanes, Silvia Nair In this work, we show that the interfacial adhesion between carbon fibers (CFs) and epoxy matrix in laminated composites can be significantly enhanced by the chemical vapor deposition (CVD) growth of multiwalled carbon nanotubes (MWCNTs) onto the fiber surfaces at low temperatures. The key process parameter was the deposition of catalytic nickel nanoparticles (NPs) onto the CFs at room temperature by a low energy double target DC sputtering system. This protocol enabled the growth of CNTs without any detrimental effect on the fiber properties, and enhanced effectively the adhesion between fibers and matrix. Fractographic investigations of single fiber/epoxy composites demonstrated an improved interfacial adhesion between the ‘hierarchical’ fibers (CF-CNT) with the epoxy matrix as compared to the bare carbon fibers. The developed protocol is versatile and it is envisioned to be easily scaled-up for volume production of CF-CNT, giving rise to high mechanical performance structural composites.

Trace fossils from the Middle and Upper Eocene (Bartonian–Priabonian) molasse deposits of the Pamplona Basin (Navarre, western Pyrenees): palaeoenvironmental implications Astibia, Humberto; Rodríguez Tovar, Francisco Javier; Díaz Martínez, Ignacio; Payros, Aitor; Ortiz, Silvia An ichnological study was carried out in the Middle–Upper Eocene sedimentary succession of the Pamplona Basin. This succession represents the molasse stage of the western part of the South Pyrenean peripheral foreland basin and extends from deep-marine turbiditic (Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl formations) and marginal marine deposits (Liédena Sandstone Member, Gendulain Formation). The tectonosedimentary evolution of the basin can also be recognized by means of the ichnoassemblages preserved throughout the succession and by the ichnofacies analysis. A total of 23 ichnogenera and at least 28 ichnospecies have been identified. The assemblage of the Ezkaba Sandstone is characteristic of the deep-sea Nereites ichnofacies. The Ophiomorpha rudis and the Paleodictyon ichnosubfacies can be differentiated in this unit, which are typical of channel axis and off-axis environments. Trace fossils in the Ardanatz Sandstone and Ilundain Marl formations, with dominance of Thalassinoides and especially Ophiomorpha, could be related to the Cruziana ichnofacies, developed in relatively low-energy environments, in semicohesive muddy substrates with intercalated silt and sand. The ichnofauna of the Liédena Sandstone Member is composed of bird tracks, and invertebrate horizontal and vertical structures. Microbial mat impressions also occur. The evidence suggests that microbial mats acted as a taphonomic bias favouring the preservation of vertebrate tracks and conditioning the presence of other trace fossils. Consequently, the assignation of this ichnofauna to a specific ichnofacies is tentative, most likely a combination of the Mermia and Scoyenia ichnofacies.

Antimicrobial susceptibility of clinical isolates of Actinomyces and related genera reveals an unusual clindamycin resistance among Actinomyces urogenitalis strains Barberis, Claudia; Budia, Mabel; Palombarani, Susana; Rodriguez, Carlos Hernan; Ramirez, Maria Soledad; Arias, Barbara; Bonofiglio, Laura; Famiglietti, Angela María Rosa; Mollerach, Marta Eugenia; Almuzara, Marisa; Vay, Carlos Alberto Objectives: Patterns of antimicrobial susceptibility in Actinomyces and related genera are very limited inthe literature. Data of predominant susceptibility profiles could contribute to the establishment of anaccurate empirical treatment.Methods: A total of 113 isolates from clinical samples were included in this study. Each isolate wasidentified using phenotypic methods and MALDI-TOF/MS. When discrepancies were observed, 16S rRNAgene sequencing was performed. The minimum inhibitory concentrations (MICs) of nine antimicrobialagents (penicillin, ceftriaxone, linezolid, tetracycline, clindamycin, erythromycin, ciprofloxacin,levofloxacin and vancomycin) were tested against the species Actinotignum schaalii (n = 23), Actinomycesturicensis (n = 18), Actinomyces europaeus (n = 13), Actinomyces naeslundii/Actinomyces viscosus group(n = 12), Actinomyces urogenitalis (n = 11), Actinomyces radingae (n = 11), Actinomyces neuii (n = 9),Actinomyces odontolyticus (n = 8), Bifidobacterium scardovii (n = 3), Actinomyces graevenitzii (n = 2),Alloscardovia omnicolens (n = 2) and Varibaculum cambriense (n = 1).Results: All of the isolates were susceptible to penicillin, ceftriaxone, vancomycin and linezolid. Almost allof the A. urogenitalis isolates (8/11) were resistant to clindamycin and showed susceptibility toerythromycin, suggesting an L-phenotype, however no determinants of clindamycin resistance (lnu andlsa genes) were detected by PCR. High MIC values to quinolones were observed in 54/113 isolates (47.8%).All of the A. urogenitalis isolates were highly resistant to ciprofloxacin and levofloxacin.Conclusions: These data highlight the importance of ongoing surveillance to provide relevant informationfor empirical management of infections caused by these organisms.© 2017 International Society for Chemotherapy of Infection and Can

Use of RNA-seq data to identify and validate RT-qPCR reference genes for studying the tomato-Pseudomonas pathosystem Pombo, Marina Alejandra; Zheng, Yi; Fei, Zhangjun; Martin, Gregory B.; Rosli, Hernan Guillermo The agronomical relevant tomato-Pseudomonas syringae pv. tomato pathosystem is widely used to explore and understand the underlying mechanisms of the plant immune response. Transcript abundance estimation, mainly through reverse transcription-quantitative PCR (RT-qPCR), is a common approach employed to investigate the possible role of a candidate gene in certain biological process under study. The accuracy of this technique relies heavily on the selection of adequate reference genes. Initially, genes derived from other techniques (such as Northern blots) were used as reference genes in RT-qPCR experiments, but recent studies in different systems suggest that many of these genes are not stably expressed. The development of high throughput transcriptomic techniques, such as RNA-seq, provides an opportunity for the identification of transcriptionally stable genes that can be adopted as novel and robust reference genes. Here we take advantage of a large set of RNA-seq data originating from tomato leaves infiltrated with different immunity inducers and bacterial strains. We assessed and validated 9 genes that are much more stable than two traditional reference genes. Specifically, ARD2 and VIN3 were the most stably expressed genes and consequently we propose they be adopted for RT-qPCR experiments involving this pathosystem.

B. cereus phospholipase C engineering for efficient degumming of vegetable oil Elena, Claudia Edicht; Cerminati, Sebastián; Ravasi, Pablo; Rasia, Rodolfo Maximiliano; Peirú, Salvador; Menzella, Hugo Gabriel; Castelli, Maria Eugenia Enzymatic phospholipid removal (degumming) is a fast-growing and environmentally friendly process for vegetable oil refining. Type C phospholipases (PLC) are the preferred enzymes since they provide an extra yield in the oil recovery. Bacillus cereus PLC can hydrolyze phosphatidylcholine (PC) but has a limited efficiency at removing phosphatidylethanolamine (PE), which together represent ∼70% of the phospholipids present in crude soybean oil. In the present work, we show that the B. cereus PLC mutant F66Y can remove up to 90% of PE while retaining its efficiency at hydrolyzing PC. Oil treatment with the engineered enzyme provides an extra yield of 1.84% making the B. cereus PLC F66Y mutant an attractive candidate for its industrial use.

Faunal assemblages of intertidal hydroids (Hydrozoa, cnidaria) from argentinean patagonia (Southwestern Atlantic Ocean) Genzano, Gabriel Nestor; Bremec, Claudia Silvia; Diaz Briz, Luciana Mabel; Costello, John H.; Morandini, Andre C.; Miranda, Thaís P.; Marques, Antonio C. This study provides taxonomical and ecological accounts for the poorly known diversity of hydroids distributed over ~2,000 km of Argentinean Patagonian intertidal habitats (42°-54°S). Sampling was performed in 11 sites with tidal amplitude between 6-13 m dominated by rocky outcrops, breakwaters, and salt marshes. Samples were sorted and identified up to the species level and hydroid associations were analyzed by multivariate analyses. A total of 26 species were recorded. The most frequent species were Amphisbetia operculata, present in 8 of the 10 sites inhabited by hydroids, followed by Symplectoscyphus subdichotomus and Nemertesia ramosa. All recorded hydroids are geographically and bathymetrically widely distributed species, common at the austral hemisphere. Seven species (Coryne eximia, Bougainvillia muscus, Ectopleura crocea, Hybocodon unicus, Halecium delicatulum, Plumularia setacea, and Clytia gracilis) were reported from intertidal fringes. Species richness differed according to the composition of the bottom, topographical complexity and density of mytilid communities. Some muddy intertidal fringes dominated by the glasswort Sarcocornia perennis had an unexpected hydroid fauna composition, never reported for salt marsh habitats, representing a remarkable novelty for the hydroid literature. The lack of studies on the hydroid fauna from these particular habitats represented a substantial gap for our biodiversity knowledge.

Sustitución de Importaciones en la Industria Biofarmacéutica Argentina: Una Estrategia con Blanco Móvil Lavarello, Pablo Jose; Goldstein, Evelin; Pita, Juan José Desde una perspectiva de sustitución de importaciones basada en la industria infantil, la protección del mercado interno es necesaria como un primer paso para generar un proceso de aprendizaje tecnológico. Esta perspectiva es de relevancia frente a la emergencia de la biotecnología como paradigma tecnológico. Para ciertos países en desarrollo como la Argentina que han alcanzado tempranamente un umbral mínimo de conocimientos y ciertas capacidades manufactureras, esto abre una ventana de oportunidad. Este trabajo muestra a partir de datos de comercio la existencia de espacio para sustitución de importaciones dependiendo de la complejidad de las tecnologías y discute ciertos aspectos para impulsar deliberadamente este tipo de estrategias.; From an infant capability approach of import substitution, domestic market protection is a necessary first step to generate technological learning. This view is relevant in the face of biotechnology paradigm emergence. For developing countries as Argentina, that had early achieved a minimum threshold of knowledge and manufacturing experience, this opens a window of opportunity. This works shows that there is space for an importation substitution strategy in Argentina depending on the complexity of technologies involved discussing some aspects to encourage deliberately this strategy.

Applied Montology Using Critical Biogeography in the Andes Sarmiento, Fausto O.; Ibarra, J. Tomás; Barreau, Antonia; Pizarro Pinochet, Jose Cristobal; Rozzi, Ricardo; González, Juan A.; Frolich, Larry M. More than most other landforms, mountains have been at the vanguard of geographical inquiry. Whether promontories, cultural works on slopes, or even metaphorical/spiritual heights, mountain research informs current narratives of global environmental change. We review how montology shifts geographic paradigms via the novel approach of critical biogeography in the Andes. We use it to bridge nature and society through indigenous heritage, local biodiversity conservation narratives, and vernacular nature–culture hybrids of biocultural landscapes (BCLs), focusing on how socioecological systems (SES) enlighten scientific query in the Andes. In our Andean study cases, integrated critical frameworks guide the understanding of BCLs as the product of long-term human–environment interactions. With situated exemplars from place naming, wild edible plants, medicinal plants, sacred trees, foodstuffs, ritualistic plants, and floral and faunal causation, we convey the need for cognition of mountains as BCLs in the Anthropocene. We conclude that applied montology allows for a multi-method approach with the four Cs of critical biogeography, a model that engages forward-looking geographers and interdisciplinary Andeanists in assessments for sustainable development of fragile BCLs in the Andes.

Foliar habit in mistletoe-host associations Glatzel, Gerhard; Richter, Hanno; Devkota, Mohan Prasad; Amico, Guillermo Cesar; Lee, Sugwang; Lin, Ruozhu; Grabner, Michael; Barlow, Bryan A. Foliar habit in parasite-host associations of mistletoes and trees is a neglected aspect in the discussion of foliar habit of woody plants. Almost all of the world’s mistletoe species are evergreen, regardless of the foliar habit of their hosts. Deciduous mistletoes are rare and confined to the northern fringes of Loranthaceae in Eurasia, and to Misodendraceae and the monotypic genus Desmaria (Loranthaceae) in southern South America. There are no deciduous mistletoes in the tropics and subtropics. Based on existing information and hypotheses on foliar habit, we asked why the majority of mistletoe species is evergreen, even on deciduous hosts, and why seasonality is apparently no driver for the evolution of deciduousness in parasite-host systems. We postulate that nutrient conservation is the main driver for evergreenness in mistletoes. Based on our own observations of wood anatomy in the host-haustorium-mistletoe continuum we hypothesize that the phenomenon of deciduousness in northerly Loranthus species is a consequence of interrupted water supply in large vessels after frost. In South Americawecould not find a consistent correlation between wood anatomy and deciduousness. We assume that deciduousness in these mistletoes evolved long ago in Antarctic forests under climatic and ecological conditions quite different from today.

Genetic variation in resistance to leaf fungus indirectly affects spider density Slinn, Heather; Barbour, Matthew A.; Crawford, Kerri; Rodriguez Cabal, Mariano Alberto; Crutsinger, Gregory M. Many host-plants exhibit genetic variation in resistance to pathogens; however, little is known about the extent to which genetic variation in pathogen resistance influences other members of the host-plant community, especially arthropods at higher trophic levels. We addressed this knowledge gap by using a common garden experiment to examine whether genotypes of Populus trichocarpa varied in resistance to a leaf-blistering pathogen, Taphrina sp., and in the density of web-building spiders, the dominant group of predatory arthropods. In addition, we examined whether variation in spider density was explained by variation in the density and size of leaf blisters caused by Taphrina. We found that P. trichocarpa genotypes exhibited strong differences in their resistance to Taphrina and that P. trichocarpa genotypes that were more susceptible to Taphrina supported more web-building spiders, the dominant group of predatory arthropods. We suspect that this result is caused by blisters increasing the availability of suitable habitat for predators, and not due to variation in herbivores because including herbivore density as a covariate did not affect our models. Our study highlights a novel pathway by which genetic variation in pathogen resistance may affect higher trophic levels in arthropod communities.

Quantitative geomorphology applied to fluvial dynamic in Aviles and Moneta basins, Tierra Del Fuego, Southern Argentina Quiroga, Diego Rubén Andrés; Gil, Veronica; Coronato, Andrea Maria Josefa The morphometric characteristics of the Moneta river basin are compared to those of the Avilés river basin. Both are located in the north of the province of Tierra del Fuego in Argentina, and they also have their catchment area in the same range: the Sierras del Bosque; runoff on the NE-oriented slopes forms the Avilés river basin, while runoff on the SE slopes forms the Moneta river basin. The analysis was made in two different scales: the first as a general scale of the basin, and the second as the catchment sector (upper, middle and lower). The quantitative analysis was applied in order to know the behavior of these two fluvial systems. For the analysis, a cartographic basis scale to 1: 20,000 was used, which was made on a mosaic of images from Google Earth®; the altimetric information was obtained throughout a digital elevation model of 45-m spatial resolution SRTM45 (Shuttle Radar Topographic Mission). The indices used were Rr, Rb, Ish and Dd to characterize the geological and geomorphological context, and Rl, Re, If, Ct and Ca to infer the behavior of the runoff in the catchment. It was established that the Moneta river basin reaches 6 in order of hierarchy; its main channel is 65.52 km long. The Re determines an elongated basin. The Ct obtained in the basin is 0.96, whereas the sub-basin level was identified to a maximum value of the O3-SM-10 (1.46). The Dd is low (1.94 km/km2), which is directly proportional to the intensity of rainfall and the slopes of the area considered. The comparison, made at the same scale, between basins determines specific fluvial characteristics of each sector (upper, middle and lower).

Identidad, verdad, responsabilidad: configuraciones discursivas de las y los nietos restituidos en la escena pública; Identity, truth, responsibility: discursive constructions of the restituted grandchildren in the public scene Quintana, María Marta En 2007, a propósito de su trigésimo aniversario, Abuelas de Plaza de Mayo publica La historia de Abuelas. 30 años de búsqueda. Se trata de un libro en el que la Asociación se presenta como un organismo socialmente legitimado, en un contexto político favorable a la causa de los derechos humanos, y en el que se traen a escena las voces de los propios nietosrestituidos. Puesson ellos quienes afirman el carácter liberador de la restitución y argumentan que la verdad, aunque conlleve dolor, siempre es preferible a la mentira, el robo, el ocultamiento. En este sentido, la publicación funciona como un marco global para las historias de los jóvenes encontrados, y es mediante esa configuración enunciativa que se produce un discurso coherente entre las afirmaciones de las Abuelas y las de los nietos. En virtud de ello, en este trabajo se examinan las configuraciones discursivas (seleccionadas y exhibidas por La Historia de Abuelas…) de las y los jóvenes restituidos. En primer lugar se problematizan las apelaciones esencialistas a ‘la sangre’, para luego avanzar en un análisis del proceso de desvelamiento de la verdad y las implicancias éticas de la restitución de identidad.; In 2007, with regard to its thirtieth anniversary, Abuelas de Plaza de Mayo publishes La historia de Abuelas. 30 años de búsqueda. This is a book in which the Association presents itself as a socially legitimated organization in a favorable political context regarding the cause of human rights, and in which the voices of grandchildren are brought on stage. It is them, who affirm the liberating character of restitution and argue that truth, even if it entails pain, it is always preferable to lies, theft and concealment. In this regard, the publication serves as a comprehensive framework for the stories of young people found, and it is through this declarative configuration that a coherent discourse between the statements of the Grandmothers and the grandchildren occurs. Against this, this paper examines the discursive configurations (selected and displayed by La historia de Abuelas...) of the returned young people. First, I problematize essentialist appeals to ‘blood’, turning afterwards to the analysis of the process of truth unveiling and finally to the ethical implications of identity restitution.

Retrieval of the optical properties of a semiinfinite compartment in a layered scattering medium by single-distance, time-resolved diffuse reflectance measurements García, Héctor Alfredo; Iriarte, Daniela Ines; Pomarico, Juan Antonio; Grosenick, D.; Macdonald, R. Functional analysis of the human brain requires methods that take the layered structure of the head into account. In this work we introduce an improved theoretical model that describes light propagation in multilayered, turbid cylinders with a infinitely thick bottom layer, which simplifies calculations and reduces computation times. Our approach was validated with Monte Carlo simulations and single distance, time-resolved experiments on a three-layered phantom, where the absorption of the deepest layer was gradually modified. We were able to retrieve both, the scattering and absorption coefficient of this layer within reasonable errors. Hereby, changes in scattering were found to have less effect on the experimental data than absorption changes, making the reliable estimation of the reduced scattering coefficient more difficult in comparison to absorption. Stability of the implemented fitting routine was thoroughly analyzed, revealing that special care is needed to obtain accurate values for the reduced scattering coefficient.

A microstructural study of acrylic-modified chitosan by means of PALS and SAXS Anbinder, Pablo Sebastián; Macchi, Carlos Eugenio; Amalvy, Javier; Somoza, Alberto Horacio Chemical modification of chitosan, specially grafting with different polymers is an important strategy in the production of bio-based materials with enhanced properties. In the present study, chitosan was grafted with n-butyl acrylate, in a surfactant-free emulsion polymerization. Stable dispersions with high grafting efficiency were obtained and the microstructure of the casted films was analyzed by positron annihilation lifetime spectroscopy and small angle X-ray scattering. Results are discussed in terms of the number and distribution of the grafting sites.

Solvatomorphs of 25,26,27,28-tetrahydroxycalix[4]arene and 5,11,17,23-tetramino-25,26,27,28-tetrabutoxycalix[4]arene: quenching photoluminescence through switching the guest Martins, Felipe Terra; Maia, Lauro June Queiroz; Da Silva Neto, Leonardo; Da Silva, Cleiton Moreira; Sarotti, Ariel Marcelo; De Fátima, Ângelo Here, we have disclosed two solid state forms of 5,11,17,23-tetramino-25,26,27,28-tetrabutoxycalix[4]arene (1) and two solid state forms of the non-functionalized 25,26,27,28-tetrahydroxycalix[4]arene (2). This is the first structural knowledge of a tetra-amino functionalized calixarene derivative, even though this compound is well known and used as a precursor of several other functionalized calix[4]arenes. The two solid forms of 1 differ by the presence of either water or water/dimethylsulfoxide (DMSO) solvent molecules entrapped in the major calixarene cavity, even though the pinched conformation is adopted in both forms as a consequence of the contacts between solvent molecules and phenyl rings. Likewise, the switch from water to DMSO in the cone cavity of 1 has abrogated the photoluminescence (PL) found only in the dihydrate form. Frontier molecular orbital calculations at the B3LYP/6-31G* level of theory support a short-range electron transfer between guest (DMSO) and host (1) molecules quenching the solid state photoluminescence when DMSO is entrapped in the cone. This solvatomorphism approach for PL search in calixarenes opens a perspective on tuning and even increasing the performance of calixarenes through changing the guest solvent molecule. Similarly, the two crystal forms of 2 entrap either methyl alcohol or DMSO in their cones, which, as well as both crystal forms of 1, are packed into sheets through different fashions and contact patterns.

Delving into the Secular Stagnation Hypothesis: A Firm-Level Analysis of the Private Sector's Excess Savings in Advanced Economies Perez Artica, Rodrigo; Brufman, Leandro; Martinez, Lisana Belén We document a persistent increase in excess savings (defined as the difference between gross savings and capital formation) and a steady decline of gross capital formation in a sample of non-financial firms from developed countries. These patterns developed even before the financial breakdown of 2007 reinforcing the case for a secular stagnation hypothesis. They go along with a deleveraging process and a decrease in the share of operating assets in total assets. We discuss three possible explanations for this long-term behavior: financial constraints, operative volatility, and the weakening of business dynamism itself.

Increased dietary levels of α-linoleic acid inhibit mammary tumor growth and metastasis Vara Messler, Marianela; Pasqualini, María Eugenia; Comba, Andrea; Silva, Renata Alejandra; Buccellati, Carola; Trenti, Annalisa; Trevisi, Lucia; Eynard, Aldo Renato; Sala, Angelo; Bolego, Chiara; Valentich, Mirta Ana The aim of this study was to determine whether α-linolenic acid (ALA ω-3 fatty acid) enriched diet affects growth parameters when applied to a syngeneic model of mammary carcinoma. Materials and methods: BALB/c mice were divided and fed with: 1) a chia oil diet, rich in ALA or 2) a corn oil diet, rich in linoleic acid (LA ω-6 fatty acid). Mice were subcutaneously inoculated with a tumor cell line LM3, derived from a murine mammary adenocarcinoma. Results: After 35 days, tumor incidence, weight, volume and metastasis number were lower in the ALA-fed mice, while tumor latency time was higher, and the release of pro-tumor metabolites derived from ω-6 fatty acids decreased in the tumor. Compared to the control group, a lower number of mitosis, a higher number of apoptotic bodies and higher T-lymphocyte infiltration were consistently observed in the ALA group. An ALA-rich diet decreased the estrogen receptor (ER) α expression, a recognized breast cancer promotor while showing an opposite effect on ERβ in tumor lysates. Conclusion: These data support the anticancer effect of an ALA-enriched diet, which might be used as a dietary strategy in breast cancer prevention.

Measurement of expansin activity and plant cell wall creep by using a commercial texture analyzer Perini, Mauro Alejandro; Sin, Ignacio Nicolás; Martinez, Gustavo Adolfo; Civello, Pedro Marcos Background Expansins play an important role in cell wall metabolism and fruit softening. Determination of expansin activity is a challenging problem since it depends on measuring cell wall properties by using ad hoc extensometers, a fact that has strongly restricted its study. Then, the objective of the work was to adapt a methodology to measure cell wall creep and expansin activity using a commercial texture meter, equipped with miniature tensile grips and an ad hoc cuvette of easy construction. Results It was possible to measure hypocotyls acid growth and expansin activity in a reliable and reproducible way, using a commercial texture meter, common equipment found in laboratories of food science or postharvest technology. Expansin activity was detected in protein extracts from cucumber hypocotyls, tomato and strawberry fruits, and statistical differences in expansin activity were found in both fruit models at different ripening stages. Conclusions The possibility of measuring expansin activity following this adapted protocol with a commercial texture meter could contribute to ease and increase the analysis of expansin in different systems, leading to a better understanding of the properties of these proteins under different experimental conditions.