Apolipoprotein D synthesis progressively increases in frontal cortex during human lifespan

Apolipoprotein D (apo D) is a lipocalin present in the nervous system that may be related to processes of reinnervation, regeneration and neuronal cell protection. In the other way, apo D expression has been correlated, in some brain regions, with normal aging and neurodegenerative diseases. To elucidate the regional and cellular expression of apo D in normal human brain during aging, we performed a detailed and extensive study in samples of post-mortem human cerebral cortices. To achieve this study, slot blot techniques, for protein and mRNA, as well as immunohistochemistry and hybridohistochemistry methods were used. A positive correlation for apo D expression with aging was found; furthermore, mRNA levels, as well as the protein ones, were higher in the white than in the grey matter. Immunohistochemistry and non-isotopic HIS showed that apo D is synthesized in both neurons and glial cells. Apo D expression is notorious in oligodendrocytes but with aging the number of neurons that synthesize apo D is increased. Our results indicate that apo D could play a fundamental role in central nervous system aging and in the reduction of products derivated from lipid peroxidation. The increment in the expression of apo D with aging can be included in a global mechanism of cellular protection to prevent the deleterious effects caused by aging

Expression of eEF1A2 is associated with clear cell histology in ovarian carcinomas: overexpression of the gene is not dependent on modifications at the EEF1A2 locus

The tissue-specific translation elongation factor eEF1A2 is a potential oncogene that is overexpressed in human ovarian cancer. eEF1A2 is highly similar (98%) to the near-ubiquitously expressed eEF1A1 (formerly known as EF1-α) making analysis with commercial antibodies difficult. We wanted to establish the expression pattern of eEF1A2 in ovarian cancer of defined histological subtypes at both the RNA and protein level, and to establish the mechanism for the overexpression of eEF1A2 in tumours. We show that while overexpression of eEF1A2 is seen at both the RNA and protein level in up to 75% of clear cell carcinomas, it occurs at a lower frequency in other histological subtypes. The copy number at the EEF1A2 locus does not correlate with expression level of the gene, no functional mutations were found, and the gene is unmethylated in both normal and tumour DNA, showing that overexpression is not dependent on genetic or epigenetic modifications at the EEF1A2 locus. We suggest that the cause of overexpression of eEF1A2 may be the inappropriate expression of a trans-acting factor. The oncogenicity of eEF1A2 may be related either to its role in protein synthesis or to potential non-canonical functions

Ultrastructural alterations in Phacus brachykentron (Euglenophyta) due to excess of organic matter in the culture medium

Morphological and ultrastructural changes induced by exposure to excess of organic matter were analyzed in Phacus brachykentron (Pochm.). The cells were isolated from sites in Matanza River, Buenos Aires, Argentina, which have a high degree of organic matter contamination coming from waste waters discharges of the meat industry. Master strains were cultured on soil water medium and a toxicity bioassay was performed. As a result of the enriched medium, several morphological and ultrastructural cellular alterations were observed by optical, scanning, and transmission electron microscopy. Among these, we can point out changes in cell dimensions, remarkable widening of some pellicle bands, increased number and volume of paramylon grains, displacement of the nucleus from the central to the lateral position, some chloroplasts with their thylakoids disordered, and cell lysis. The response to organic enrichment was very fast, i.e. during the 48 h of the bioassay. Therefore, any significant increase of organic matter would rapidly affect wild euglenoids. Our results suggest that the alterations observed, such as the presence of large intracellular paramylon bodies or the deformation of euglenoid cells in natural samples, have the potential to be used as environmental bioindicators.Fil: Nannavecchia, Paula Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Tolivia, Analía Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Conforti, Visitacion Teresa D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Chemical constituents and biological activity of Euglena gracilis extracts

Background: Euglena gracilis is a microalgae with a wide range of nutritional requirements,suggesting the existence of diverse physiological patterns. The aim of this work is to carry out a study about secondary metabolites biosynthesis on two strains of E. gracilis cultured in vitro. Methods: Extracts from a Euglena gracilis (Klebs) commercial strain and a wild type isolated from an urban polluted river (MAT) were screened for preliminary identification of chemical constituents. Both strains were studied in their photosynthetic and bleached forms, on their exponential and stationary growth phases. Chromatographic analysis of pigments, lipids, and flavonoids were performed. Besides antioxidant, growth inhibition, and toxic activity were tested in vitro. Results: The phytochemical analysis of extracts indicated the presence of steroids in all samples, cardenolids and triterpenes in the exponential growth phase. With the exception of the photosynthetic MAT strain, tannins were present in all the other on exponential phase samples and flavonoids were only observed in the stationary phase of both photosynthetic strains. Chromatographic profiles show that chlorophyll content decreased while carotenoids content increased in the stationary phase of both photosynthetic strains, and reveal the presence of flavonols derived from quercetin. In concordance with the presence of polyphenols, the fractions with the highest polarity showed antioxidant activity against DPPH and growth inhibition activity in vitro even in the absence of paramylon, previously reported to have antitumoral properties. Conclusion: This work constitutes the first report about polyphenol production in Euglenoids, which allows us a first assessment of the potential of E. gracilis as a source of bioactive products.Fil: Tolivia, Analía Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Conforti, Visitacion Teresa D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Córdoba, Osvaldo León. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Flores, Maria Lujan. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentin

Enzimas antioxidantes en la maduración de carne de vacuno procedente de dos cabañas autóctonas asturianas

Antioxidant enzymes throughout ageing from two local cattle breeds In this study, meat from double-muscled (“culones”, mh/mh) and normal (+/+) young bulls of the breed Asturiana de los Valles (AV) as well as normal (+/+) animals from Asturiana de la Montaña (AM) was analysed during ageing at 4°C with regard to its oxidative status. Activities of the following main antioxidant enzymes were determined: Superoxide dismutase (SOD), Catalase (CAT) and Glutathione reductase (GR). In both breeds (AV and AM), lipid peroxidation (LPO) was also measured throughout the ageing period, because meat shelf life is mainly limited by lipids and proteins. All enzymes were apparently stable during meat ageing. While GR exhibited the lowest activity among antioxidant enzymes, SOD and CAT showed activity along the ageing period studied, with similar activity pattern seen in both double-muscled and normal animals, although, being advanced in the formers. In normal animals of both the AV and AM breeds, lipid peroxidation did not vary during ageing. However, double- muscled meat showed a significant increase after 7 days of maturation.En este trabajo se determinó el estado oxidativo de la carne procedente de terneros añojos de genotipo culón (mh/mh) y normal (+/+) de la raza Asturiana de los Valles (AV) así como terneros normales (+/+) de la raza Asturiana de la Montaña (AM) durante su periodo de maduración a 4ºC, mediante el estudio de la actividad de los principales enzimas antioxidantes: Superóxido dismutasa (SOD), Catalasa (CAT) y Glutatión reductasa (GR). Se midió también el nivel de peroxidación lipídica (LPO) a lo largo de la maduración a 4ºC de carne procedente de ambas razas (AV y AM) por ser los lípidos y las proteínas las biomoléculas que más limitan la vida media de la carne durante este periodo. Los resultados reflejaron una clara estabilidad de los enzimas durante el periodo de maduración de la carne, siendo el enzima GR el que mostró menor actividad, mientras que SOD y CAT presentaron actividad a lo largo de todo el período de maduración estudiado con un patrón de actividad que se repitió en la carne de terneros (mh/mh) y (+/+) de raza AV, siendo más adelantado en los primeros que en los segundos. La peroxidación lipídica no mostró variación alguna a lo largo de la maduración tanto en animales (+/+) de la raza AV como en animales (+/+) de la raza AM. Sin embargo, los animales (mh/mh) de la raza AV mostraron un incremento significativo del daño lipídico en el músculo tras 7 días de maduración