Biología

In normal embryonic fibroblasts, the Na + /H + exchanger regulator factor 1 (NHERF1) stabilizes Ecadherin/β-catenin binding and the lack of NHERF1 expression promotes cell transformation thus acting as a tumor suppressor gene. We here tested the hypothesis that NHERF1 could act as a tumor suppressor gene in colon cancer as a mediator of estrogens' protective actions in colon carcinogenesis. We studied the expression and localization of NHERF1 and β-catenin by immunohistochemistry in colonic tumors induced by 1,2 dimethylhidrazine (DMH) in Sprague-Dawley rats. One group of the rats treated with the carcinogen was ovariectomized (OVX) in the middle of the tumor induction, simulating a human menopausal condition. We observed a protective role of estrogens in colon cancer, as non-ovariectomized rats (DMH) had a reduced tumor area compared with the ovariectomized group (DMH+OVX; mean±SE) 28.98±4.65 vs. 67.58±8.69 (p<0.00380). Despite the lack of plasma estrogen stimulation, we found abundant expression of NHERF1 in colon tumors from ovariectomized rats. NHERF1 was mainly localized in the cytoplasm of the adenocarcinoma cells and lost the apical localization previously reported in normal colon tissue. We also detected expression of NHERF1 by western blot in the SW48, CACO-2, and HT29 colon cancer cell lines. Non-estrogenic factors in plasma or the tumor microenvironment may regulate NHERF1 expression in transformed colon epithelial cells. Further studies are required to understand the regulation of NHERF1 expression in colon cancer tissue.

The type A of neurotoxin produced by Clostridium botulinum is the prevalent serotype in strains of Mendoza. The soil is the main reservoir for C.botulinum and is possibly one of the infection sources in infant botulism. In this study, we characterized and compared autochthonous C. botulinum strains and their neurotoxins. Bacterial samples were obtained from the soil and from fecal samples collected from children with infant botulism. We first observed differences in the appearance of the colonies between strains from each source and with the A Hall control strain. In addition, purified neurotoxins of both strains were found to be enriched in a band of 300 kDa, whereas the A-Hall strain was mainly made up of a band of ~600 kDa. This finding is in line with the lack of haemagglutinating activity of the neurotoxins under study. Moreover, the proteolytic activity of C. botulinum neurotoxins was evaluated against SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) proteins from rat brain. It was observed that both, SNAP 25 (synaptosomal-associated protein 25) and VAMP 2 (vesicle-associated membrane protein) were cleaved by the neurotoxins isolated from the soil strains, whereas the neurotoxins from infant botulism strains only induced a partial cleavage of VAMP 2. On the other

ABSTRACTNeuronal excitotoxicity induced by glutamatergic receptor overstimulation contributes to brain damage. Recent studies have shown that lysosomal membrane permeabilization (LMP) is involved in ischemia-associated neuronal death. In this study we evaluated the effect of neonatal hypoxia-ischemia (HI), as a model of excitotoxicity, on the lysosomal integrity throughout the distribution of the lysosomal proteins cathepsin D and prosaposin. Rat pups (7 days old) of the Wistar Kyoto strain were submitted to HI and they were euthanized 4 days after treatment and the cerebral cortex (Cx) and hippocampus (HIP) were processed for immunohistochemistry or immunoblotting. Treatment induced an increase of gliosis and also a redistribution of both prosaposin and cathepsin D (as intermediate and mature forms), into the cytosol of the HIP and Cx. In addition, HI induced a decrease of LAMP-1 in the membranous fraction and the appearance of a reactive band to anti-LAMP-1 in the cytosolic fracti...

The aqueous extract of the Argentinean native plant, Prosopis strombulifera (PsAE), presents cytotoxicity against human cancer cell lines by inducing cytostasis, necrosis and apoptosis; with diminution of clonogenic survival; without genotoxic effects nor oral animal toxicity. Until now, the chemical extract composition and its in vivo antitumoral properties remain unknown; these studies are the aim of the current work. The PsAE was characterized by chemical fingerprinting and the metabolome was identified by tandem UHPLC-PDA-HESI-Q-orbitrap® mass spectrometry. Colorectal tumors were induced by DMH administration and melanomas resulted from B16-F0 S.C. cells injection; then, animals were treated orally with PsEA. To correlate in vivo results with in vitro cytotoxicity, B16-F0 cell were cultured to determine: cell proliferation and viability by dye exclusion assays, MTT and CFSE dilution; cell cycle distribution by flow cytometry; and immunoblotting of p21 cip1 , PCNA, cleaved caspase 3, cleaved PARP and TUBA1A. Based on UHPLC-OT-MS and PDA analysis, twenty-six compounds were identified, including: 5 simple organic acids, 4 phenolic acids, 4 procyanidins, 11 flavonoids, and 2 oxylipins. On C57BL6 mice, PsAE significantly increases the median survival on colorectal cancer and reduces the final volume and weight of melanomas. Over cultured cells, the treatment induce over-expression of p21, cytostasis by G2/M cell cycle arrest and apoptosis; while, on in vivo melanomas, treatment up-regulates p21 and slightly decreases PCNA. In conclusion, PsAE is composed by phenolic compounds which demonstrate cytotoxic and antitumoral properties when is orally administrated. Presented results support future research of PsAE as a potential phytomedicine for cancer treatment.

Este estudio aborda la problemática, dentro del campo didáctico de la enseñanza de la Biología Humana, de la construcción de conceptos sobre el funcionamiento cerebral en interacción con sustancias adictivas, en el marco de la educación secundaria. El desarrollo del mismo se enfocó en: 1) rescatar las concepciones de los estudiantes acerca de la estructura-función del sistema nervioso en general; 2) relevar la relación que establecen entre algunas sustancias psicoactivas (alcohol, marihuana y tabaco), el funcionamiento cerebral y el impacto sobre otras funciones orgánicas; 3) relevar la potencialidad de la formación de conductas de protección de la salud.El abordaje metodológico incluyó la resolución de un estudio diagnóstico-intervencionista, en cuatro establecimientos educativos, en aulas de segundo año de educación secundaria, en Mendoza, Argentina. En éste se implementaron estudios de pre y post-test mediante un instrumento validado. Se desarrolló en toda la muestra poblacional ...

Background and aim: Prosopis strombulifera (Lam.) Benth is a rhizomatous shrub native from different zones of Argentine Republic. P. strombulifera aqueous extract (PsAE) has different effects and several biological activities have been reported. The goal of this study was to analyze the activity of PsAE on a murine model of cutaneous leishmaniasis caused by Leishmania amazonensis. Experimental procedure: PsAE was orally administered at 150 mg/animal/day on BALB/c mice infected in the right footpad (RFP) with 1 Â 10 5 promastigotes of L. amazonensis. As a chemotherapeutic control of treatment, animals receive a commercial form of meglumine antimoniate (MA) (Glucantime®, Aventis, Paris, France). Results and conclusion: We observe that the size of RFP lesions of infected mice without treatment showed a grade of inflammation, ulceration and necrosis at the site of infection much greater than that observed with PsAE or MA treatment. Moreover, PsAE was capable of decreasing parasite burden and splenic index. Furthermore, PsAE treated mice showed a significant decrease in O.D. of total anti-Leishmania IgG antibody responses against L. amazonensis. This decrease was similar to those observed when the reference drug, MA, was used. This would indicate that PsAE treatment inhibits or delays disease progression in mice. In conclusion, our findings suggest that PsAE could be a potential candidate to be used, as a new therapeutic strategy, to treat cutaneous leishmaniasis caused by L. amazonensis.

El perfil de desarrollo que motoriza el crecimiento económico con una distribución equitativa del ingreso y con mejores condiciones sociales está en crisis. Existen planes estratégicos en los que intervienen diferentes actores sociales pero no siempre se conocen los procesos de gestión de los mismos. La identidad del departamento agroindustrial que durante muchas décadas representó mayoritariamente el sector productivo, está conformada por pequeños (minifundios), medianos productores y pequeñas empresas, vulnerables ante la economía globalizada. La mayoría de los integrantes de estos sectores presentan un comportamiento de sectores productivos en el departamento de San Rafael a fin de conocer la evolución y composición de las actividades económicas más relevantes de los sectores primarios, secundarios y terciarios, identificando el potencial endógeno, estos elementos involucrar al futuro como causa final del presente. facilitar la tarea a quienes ejercen la causalidad eficiente del futuro, son los Actores Sociales y en esto reside la responsabilidad de construir el futuro.

RESUME. Nous presentons un projet de recherche en cours visant a ameliorer les interactions d’utilisateurs de differentes categories professionnelles avec un systeme d’information dedie au droit du transport et de la logistique. L’objectif vise a concevoir et a mettre au point un environnement numerique de travail (ENT) destine a un public professionnel (entreprises de la filiere logistique, juristes, risk managers, assureurs, avocats, ...) et non professionnel (usagers ou salaries des transports). Apres avoir pose la question de l’appropriation des contenus dans le cadre des documents numeriques, nous decrirons les specificites de notre corpus de travail. Nous placerons alors notre projet dans un cadre theorique actuellement novateur au sein des sciences cognitives, celui de l’enaction. Ceci nous amenera a proposer une approche resolument centree utilisateur dans la conception de l’ENT. Nous terminerons par une description des specifications du futur ENT, qui privilegie une demarch...

Anthocyanin profiles are commonly used for grapevine cultivar identification because it is currently accepted that this trait is closely related to their genetic characteristics. Nevertheless, the extent of the variation for the anthocyanin profiles among clones of the same cultivar has not yet been studied in depth. The relative concentration of anthocyanins of 131 Malbec clones grown in the same vineyard was investigated by HPLC-DAD and the use of comprehensive statistic procedures. Complementarily, the expression level of structural and regulatory genes was studied via real time polymerase chain reaction. Significant variation was identified among the profiles of the clones, mainly due to variations in the amounts of malvidin derivatives. Finally, the differential expression in F3′5′H, OMT1 and AM2 genes seems to be related to the malvidin content variation. This work shows the existence of variation for the anthocyanin profiles among clones from the same grapevine cultivar and the putative involvement of genes related to hydroxylation, methylation, and transport of anthocyanins on the basis of such variation.

A conventional PCR targeted directly to the detection of Shiga toxin-producing Escherichia coli (STEC) in diarrheal stools of symptomatic patients may require the introduction of internal controls to detect false negative results. In the present study, we designed a competitive internal amplification control (IAC) to be included in a well-known PCR protocol used to amplify the stx1and stx2 genes from STEC isolates. The IAC was introduced in the PCR reaction and amplified when E. coli O157:H7 cultures and contaminated pediatric feces were assayed. When STEC concentration was 10 3 CFU ml-1 in pure culture and 10 4 CFU g-1 in contaminated stools, the IAC at concentration of 0.143 pg µl-1 in the PCR reaction mixture was co-amplified with the stx2 sequence, producing bands of 279 and 349 bp, respectively. These STEC values were considered the detection limits of the duplex PCR. The specific detection of STEC by duplex PCR including IAC might be achieved directly on pediatric feces when the pathogen load reaches concentrations of at least 10 4 CFU g-1 .

The aim of this chapter is to provide a description of the latest scientific advances in the field of gene functional analysis in grapevine. It provides general information about the studies conducted during the past decade to understand the natural variation of this plant and how this information has been exploited for the understanding of traits of interest. Likewise, it is exposed how the use of biotechnology tools have helped to characterize the mechanisms of gene expression and its regulation, as well as the subcellular localization of proteins and their interactions with other molecules. Finally, an approximation to the new technologies of gene editing and their potential application in the functional study of grapevine has been carried out.

The analyses of the grapevine (Vitis vinifera L.) genome have revealed an unusually large and closely related stilbene synthase (VvSTS) gene family. Interestingly, despite the high sequence similarity among those genes, several studies have observed clear differences between their expression patterns. Here, we studied the transcriptional responses to different elicitors of several VvSTSs in cellular suspension cultures. Primarily, we performed the in silico analysis of the VvSTS regulatory sequences and found the presence of several putative cis-regulatory elements. Then, we evaluated the effect of three treatments-naphtalene acetic acid, methyl jasmonate (MeJA), and ethylene-over the gene expression and found that the genes follow expression patterns probably specific to their sequences. According to this, we focused our study on their regulatory regions and adopted a novel and efficient transient expression assay to determine the activity of these promoters. The results demonstrated that variation in gene expression could be assessed through the analysis of VvSTS regulatory sequences under the effect of different stimuli such as MeJA and cyclodextrins. Furthermore, taking advantage of the lower sequence identity at the promoter level, this strategy accomplished a more accurate alternative to differentiate the members of a large multi-gene family such as STS.

ABSTRACTCarrot (Daucus carota L.) is one of the most cultivated vegetable in the world and of great importance in the human diet. Its storage organs can accumulate large quantities of anthocyanins, metabolites that confer the purple pigmentation to carrot tissues and whose biosynthesis is well characterized. Long non-coding RNAs (lncRNAs) play critical roles in regulating gene expression of various biological processes in plants. In this study, we used a high throughput stranded RNA-seq to identify and analyze the expression profiles of lncRNAs in phloem and xylem root samples using two genotypes with a strong difference in anthocyanin production. We discovered and annotated 8484 new genes, including 2095 new protein-coding and 6373 non-coding transcripts. Moreover, we identified 639 differentially expressed lncRNAs between the phenotypically contrasted genotypes, including certain only detected in a particular tissue. We then established correlations between lncRNAs and anthocyanin...