Alkane-grown Beauveria bassiana produce mycelial pellets displaying peroxisome proliferation, oxidative stress, and cell surface alterations

The entomopathogenic fungus Beauveria bassiana is able to grow on insect cuticle18 hydrocarbons as the sole carbon source, inducing several enzymes involved in alkane19 assimilation and concomitantly increasing virulence against insect hosts. In this study, we20 describe some physiological and molecular processes implicated in growth, nutritional21 stress response, and cellular alterations found in alkane-grown fungi. The fungal cytology22 was investigated using light and transmission electron microscopy (TEM) while the surface23 topography was examined using atomic force microscopy (AFM). Fungal hydrophobicity24 was also measured on the cell surface. Additionally, the expression pattern of several genes25 associated with oxidative stress, peroxisome biogenesis, and hydrophobicity were analysed26 by qPCR. We found a novel type of growth in alkane-cultured B. bassiana similar to27 mycelial pellets described in other alkane-free fungi, which were able to germinate and28 produce viable conidia in media without a carbon source and to be pathogenic against29 larvae of the beetles Tenebrio molitor and Tribolium castaneum. Optical microscopy and30 TEM showed that pellets were formed by hyphae cumulates with high peroxidase activity,31 exhibiting peroxisome proliferation and an apparent surface thickening. Alkane-grown32 conidia appeared to be more hydrophobic and cell surfaces displayed different topography33 than glucose-grown cells, as it was observed by AFM. We also found a significant34 induction in several genes encoding for peroxins, catalases, superoxide dismutases, and35 hydrophobins. These results show that both morphological and metabolic changes are36 triggered in mycelial pellets derived from alkane-grown B. bassiana.Fil: Huarte Bonnet, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Santos Da Paixao, Flavia Regina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Ponce, Juan C. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Santana, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Prieto, Eduardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Pedrini, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin

Estudio de un producto auxiliar no iónico como alternativa al electrolito en la tintura de la lana

Il s’agit d’une étude sur l’application d’un nouveau produit auxiliaire de type non ionique, proposé pour remplacer l’électrolyte dans la teinture de la laine. En outre, à partir des études menées par les auteurs sur des applications enzymatiques dans la teinture de la laine, ils ont essayé d’établir les effets synergiques qui résulteraient éventuellement de l’utilisation d’une enzyme avec le nouveau produit auxiliaire de type non ionique. Ils ont ensuite comparé les résultats d’absorption de colorant, les différences de couleur sur les articles teints et certaines solidités entre les teintures à basse température effectuées selon un système conventionnel comme l’électrolyte et les teintures où l’électrolyte est remplacée par le nouveau produit non ionique, une enzyme ou les deux en même temps. Ils ont aussi déterminé certains paramètres écologiques (DQO, DBO, pH et conductivité) dans les bains résiduels des différentes teintures étudiées.El presente trabajo es un estudio de aplicación de un nuevo producto auxiliar de tipo no iónico que se propone como sustituto del electrolito en la tintura de la lana. Además, tomando como base los estudios llevados a cabo por los autores sobre aplicaciones enzimáticas en la tintura de lana, se intentan establecer los posibles efectos sinérgicos al utilizar un enzima junto con el nuevo producto auxiliar de tipo no iónico. Se comparan los resultados de absorción de colorante, diferencias de color en los artículos teñidos, así como algunas solideces entre: tinturas a baja temperatura efectuadas según un sistema convencional con electrolito y tinturas en las que se sustituye el electrolito por el nuevo auxiliar no iónico, por un enzima o por ambos simultáneamente. También se han determinado algunos parámetros ecológicos (DQO, DBO, pH y conductividad) en los baños residuales de las diferentes tinturas estudiadas.This paper is an application study of a new auxiliary product non-ionic type, proposed as an electrolyte substitutive in wool dyeing. This paper intends to establish the possible synergetic effects on using an enzyme together with the new non-ionic auxiliary product. Results of dye absorption, colour differences in the dyed samples, and some colour fastness are compared between a conventional dyeing system with electrolyte and dyeing systems in which the electrolyte is substituted by the new non-ionic auxiliary, by an enzyme or by both simultaneously. Some ecological parameters (COD, BOD, pH and conductivity) have been determined in the residual baths of the different dyeings examined

Semliki forest virus vectors engineered to express higher IL-12 levels induce efficient elimination of murine colon adenocarcinomas

To evaluate the use of alphavirus vectors for tumor treatment we have constructed and compared two Semliki Forest virus (SFV) vectors expressing different levels of IL-12. SFV-IL-12 expresses both IL-12 subunits from a single subgenomic promoter, while in SFV-enhIL-12 each IL-12 subunit is expressed from an independent subgenomic promoter fused to the SFV capsid translation enhancer. This latter strategy provided an eightfold increase of IL-12 expression. We chose the poorly immunogenic MC38 colon adenocarcinoma model to evaluate the therapeutic potential of SFV vectors. A single intratumoral injection of 10(8) viral particles of SFV-IL-12 or SFV-enh-IL-12 induced>or=80% complete tumor regressions with long-term tumor-free survival. However, lower doses of SFV-enhIL-12 were more efficient than SFV-IL-12 in inducing antitumoral responses, indicating a positive correlation between the IL-12 expression level and the therapeutic effect. Moreover, repeated intratumoral injections of suboptimal doses of SFV-enhIL-12 increased the antitumoral response. In all cases SFV vectors were more efficient at eliminating tumors than a first-generation adenovirus vector expressing IL-12. In addition, the antitumoral effect of SFV vectors was only moderately affected by preimmunization of animals with high doses of SFV vectors. This antitumoral effect was produced, at least partially, by a potent CTL-mediated immune response

Percepção das organizações de pessoas deficientes sobre o tratamento que a mídia dá às pessoas deficientes nos espaços noticiosos

El tratamiento que los medios de comunicación dan a las personas con discapacidad es un asunto importante para su movimiento asociativo, que busca la inclusión y participación activa de las personas con discapacidad en todos los ámbitos de la sociedad. Aunque se ha avanzado en el modo en el que los medios informan sobre la discapacidad, persiste la preocupación en el colectivo por el tipo de noticias y los marcos desde los que se abordan. La metodología cualitativa del estudio es la entrevista semiestructurada a federaciones y confederaciones asociadas al Comité Español de Representantes de Personas con Discapacidad (Cermi). Los resultados apuntan a que persisten las perspectivas paternalistas o capacitistas que alejan la imagen mostrada de la realidad del colectivo. Se observan discrepancias entre los casos de las personas ciegas o con síndrome de Down, con una representación más ajustada, y las personas con discapacidad psicosocial, cuyo caso sigue estando estigmatizado. Las organizaciones ponen el foco en la mejora de la formación y la especialización de los profesionales de la información, así como en la colaboración con el colectivo para mejorar el tratamiento mediático. Se puede concluir que el espacio informativo dedicado sigue siendo insuficiente, estereotipado y desigual entre los distintos tipos de discapacidad.The media's treatment of people with disabilities is an important issue for their associative movement, which seeks the inclusion and active participation of people with disabilities in all areas of society. Although progress has been made in the way in which the media report on disability, there is still concern in the group about the type of news and the frameworks from which they are approached. The qualitative methodology of the study is the semi-structured interview with federations and confederations associated with the Spanish Committee of Representatives of People with Disabilities (Cermi). The results point to the persistence of paternalistic or ableist perspectives that distance the image portrayed from the reality of the collective. Discrepancies are observed between the cases of blind people or people with Down syndrome, with a more accurate representation, and people with psychosocial disabilities, who are still stigmatized. The organizations put the focus on improving the training and specialization of professionals, as well as on collaborating with the associative movement to improve the media treatment of disability. It is concluded that the media space dedicated to them is still insufficient, stereotyped and unequal between the different types of disability.O tratamento da pessoa com deficiencia na mídia é uma questão importante para seu movimento associativo, que busca a inclusão e a participação ativa das pessoas com deficiência em todas as esferas da sociedade. Embora tenham sido feitos progressos na forma como a mídia reporta sobre deficiência, ainda há preocupação entre o grupo sobre o tipo de notícias e os quadros a partir dos quais elas são abordadas. A metodologia qualitativa do estudo é uma entrevista semi-estruturada com federações e confederações associadas ao Comitê Espanhol de Representantes de Pessoas com Deficiência (Cermi). Os resultados apontam para a persistência de perspectivas paternalistas ou fortalecedoras que distanciam a imagem mostrada da realidade do grupo. Observam-se discrepâncias entre os casos de cegos ou pessoas com síndrome de Down, com uma representação mais precisa, e pessoas com deficiências psicossociais, cujo caso ainda é estigmatizado. As organizações se concentram em melhorar o treinamento e a especialização dos profissionais da informação, bem como em colaborar com o grupo para melhorar a cobertura da mídia. Pode-se concluir que o espaço de informação dedicado a esta questão ainda é insuficiente, estereotipada e desigual entre os diferentes tipos de deficiência

Processes of Objectification Around Geometric Ideas in the Production of Simulators with Geogebra

En líneas generales, la investigación se centra en el aprendizaje geométrico manifestado por un alumno cuando comunica a dos profesores la técnica de construcción de un semicírculo con GeoGebra. Desde una perspectiva histórico-cultural, dicho aprendizaje es analizado en atención a los procesos de objetivación de saberes geométricos que tuvieron lugar durante la comunicación de la técnica, empleando para ello un análisis multi-semiótico. Los resultados destacan algunos aspectos de los procesos de objetivación evidenciados en el análisis, tales como la actividad semiótica desplegada, la actuación de los profesores y los problemas surgidos a lo largo de la comunicación de la técnica.In general, the research focuses on the geometric learning revealed by a student who communicates to two teachers the technique of constructing a semicircle with GeoGebra. From a historical-cultural perspective, this learning is analysed in response to the processes of objectification of geometric knowledge that took place during the communication of the technique, using a multi-semiotic analysis. The results highlight some aspects of the processes of the objectification evidenced in the analysis, such as the semiotic activity deployed, the performance of the teachers and the problems that arise during the communication of the technique

El uso experimental del GeoGebra en un contexto de formación docente en matemática

En los últimos años, las actividades mediadas por tecnologías digitales han tenido mayor presencia en la educación matemática. Una de estas actividades es la diagramación con GeoGebra, cuya finalidad es la obtención de dibujos dinámicos que modelen objetos de la realidad, utilizando para ello las herramientas de construcción y medida que integra el GeoGebra. Sin embargo, poco se conoce sobre este uso para resolver las tareas de diagramación. En este sentido, el objetivo de este trabajo es describir parte de una experiencia de diagramación con GeoGebra en un contexto de formación docente, centrando la atención en el “uso experimental” del software por parte de estos sujetos. Para lograr esto usamos el enfoque experimental planteado en el marco teórico Humanos-con-medios, propuesto por Borba y Villareal (2005), para analizar un uso experimental del GeoGebra por parte de los profesores para dar respuesta a una tarea de diagramación

In situ detection of AE2 anion-exchanger mRNA in the human liver

Na+-independent anion exchangers, a family of membrane proteins that mediate electroneutral exchanges of chloride and bicarbonate ions across the cell membrane, are considered to be involved in intracellular pH regulation as well as in transepithelial acid/base transport. Previous immunohistochemical data have shown that anion-exchanger-2 (AE2) protein is expressed in the liver parenchyma, localizing at both the canaliculi and the luminal surfaces of intrahepatic bile ducts, where it may have a role in the biliary secretion of bicarbonate. In the present study, we have carried out in situ hybridization experiments on biopsies of human liver using three overlapping antisense anion-exchanger-2 riboprobes. Anion-exchanger-2 mRNA signals were localized mainly in the cytoplasm of terminal and interlobular bile-duct cells, whereas weaker signals were observed in bile-duct cells of larger intrahepatic ducts. Furthermore, some hepatocytes, mostly periportal, contained detectable anion-exchanger-2 mRNA signals in their cytoplasm. No hybridization signals were observed in controls with sense riboprobes, with omission of the antisense probe, or with treatment of the sections with RNase before hybridizations. Finally, intense anion-exchanger-2 hybridization signals were observed in lymphomononuclear cells in sinusoids and in portal infiltrates. Immunocytochemical data from reverse-phase sections suggest that these cells correspond to some of the CD45R+ (UCHL1+) T lymphocytes resident in the liver

Specific effect of arachidonic acid on 17β-hydroxysteroid dehydrogenase in rat Leydig cells

AbstractIt is well known that arachidonic acid (AA) acts as an intratesticular factor regulating luteinizing hormone-mediated testicular steroidogenesis. The present studies were conducted to determine the effect of AA on steroidogenic enzymes in rat Leydig cells. Exogenously added AA significantly inhibited 22(R)-hydroxy-cholesterol-stimulated testosterone production, which is a clear indication that AA is acting at some point after cholesterol transport to the inner mitochondrial membrane. AA failed to block the conversion of 22(R)-hydroxycholesterol to pregnenolone, indicating that the cytochrome P-450 side-chain cleavage enzyme complex is not the site of inhibition. The present results demonstrate that only 17β-hydroxysteroid dehydrogenase seems to be involved in the AA action, since nearly 60% inhibition of testosterone production was found when the cells were incubated with androstenedione. Furthermore, no effect of AA was found when androstenediol was used as substrate in the testosterone synthesis, which indicates that 3β-hydroxysteroid dehydrogenase is not affected by AA. The conversion of AA to its metabolites is not required for its action on 17β-hydroxysteroid dehydrogenase and the activation of protein kinase C is not involved in the inhibitory effect