Regulación de las enzimas desaturantes en la diabetes mellitus experimental

Durante el desarrollo del presente trabajo de tesis se utilizaron diferentes modelos de Diabetes Mellitus de rata, de tipo I inducida y de tipo II, inducida o genética, teniendo como objetivos principales: a) Estudiar el rol regulador que tienen sobre el metabolismo de la biosíntesis de ácidos grasos, a través de las desaturasas hepáticas, las vías de activación dependientes de: - Insulina/SREBP-1c - PPAR-α - LXR-α b) Realizar un estudio pormenorizado de las interacciones entre las distintas vías de regulación antes mencionadas, y del resultado de estas interacciones sobre el metabolismo de las desaturasas hepáticas y sobre las composiciones de ácidos grasos de membrana de hígado. c) Realizar un aporte a la elucidación de la compleja red reguladora de la biosíntesis de ácidos grasos en el hígado de mamíferos y de las alteraciones que pueden ocurrir como consecuencia de la patología diabética de tipo I o II. d) Determinar las influencias diferenciales de cada tipo de diabetes (I versus II) sobre: - el nivel de expresión de SCD1, Δ6 y Δ5 desaturasas de ácidos grasos hepáticas, en rata. - la actividad enzimática de las desaturasas hepáticas. - las composiciones de ácidos grasos de membranas celulares, microsomales hepáticas o de las fracciones que resulten de interés en el experimento en particular, resultantes de las alteraciones producidas en los puntos anteriores.Facultad de Ciencias Exacta

Methylation of the Gpat2 promoter regulates transient expression during mouse spermatogenesis

Spermatogenesis is a highly regulated process that involves both mitotic and meiotic divisions, as well as cellular differentiation to yield mature spermatozoa from undifferentiated germinal stem cells. Although Gpat2 was originally annotated as a glycerol-3-phospate acyltransferase by sequence homology to Gpat1 , GPAT2 is highly expressed in testis but not in lipogenic tissues and is not up-regulated during adipocyte differentiation. New data show that GPAT2 is required for the synthesis of piRNAs, a group of small RNAs that protect the germ cell genome from retrotransposable elements. In order to understand the relationship between GPAT2 and its role in the testis, we focused on Gpat2 expression during the first wave of mouse spermatogenesis. Gpat2 expression was analyzed by qPCR, in situ hybridization, immunohistochemistry and Western blot. Gpat2 mRNA content and protein expression were maximal at 15 dpp and restricted to pachytene spermatocytes. To achieve this transient expression, both epigenetic mechanisms and trans-acting factors are involved. In vitro assays showed that Gpat2 expression correlates with DNA demethylation and histone acetylation and that it is up-regulated by retinoic acid. Epigenetic regulation by DNA methylation was confirmed in vivo in germ cells by bisulfite sequencing of the Gpat2 promoter. Consistent with the initiation of meiosis at 11 dpp, methylation decreased dramatically. Thus, Gpat2 is expressed at a specific stage of spermatogenesis, consistent with piRNA synthesis and meiosis I prophase, and its on-off expression pattern responds predominantly to epigenetic modifications.Fil: Garcia Fabiani, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Montanaro, Mauro Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Lacunza, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; ArgentinaFil: Cattaneo, Elizabeth Renee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Coleman, Rosalind A.. University of North Carolina; Estados UnidosFil: Pellon Maison, Magali. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Gonzalez-Baró; MR. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin

Displacement Damage dose and DLTS Analyses on Triple and Single Junction solar cells irradiated with electrons and protons

Space solar cells radiation hardness is of fundamental importance in view of the future missions towards harsh radiation environment (like e.g. missions to Jupiter) and for the new spacecraft using electrical propulsion. In this paper we report the radiation data for triple junction (TJ) solar cells and related component cells. Triple junction solar cells, InGaP top cells and GaAs middle cells degrade after electron radiation as expected. With proton irradiation, a high spread in the remaining factors was observed, especially for the TJ and bottom cells. Very surprising was the germanium bottom junction that showed very high degradation after protons whereas it is quite stable against electrons. Radiation results have been analyzed by means of the Displacement Damage Dose method and DLTS spectroscopy.Comment: Abstract accepted for poster session at 2017 IEEE Nuclear and Space Radiation Effects Conference, July 17-21, New Orlean

Pea (Pisum sativum) and faba bean (Vicia faba L.) seeds as protein sources in growing-finishing heavy pig diets: effect on growth performance, carcass characteristics and on fresh and seasoned Parma ham quality

The effect of pea and faba bean inclusion in growing-finishing heavy pig diets was evaluated. The following iso-lysinic and iso-energetic diets offered to the pigs in three phases (40-80; 80-120; 120-160 kg) were compared: CTR, control diet with soybean meal (SBM) as protein source; RP, CTR diet where pea replaced SBM; RF, CTR diet where faba bean replaced SBM. 126 animals were randomly distributed in 3 homogeneous groups with 42 animals each (7 pens with 6 animals each per treatment). The RP and RF diets did not negatively affect the carcass characteristics both of the pigs slaughtered at the conventional weight (127.5 kg) and heavy pigs (158.5 kg). The pigs fed the RP and RF diets ate similarly to the pigs fed the CTR overall the trial but RF pigs grew better than CTR animals. The subcutaneous fat of the fresh hams destined for Parma ham production and obtained from pigs fed RP diet had a higher omega 3 fatty acid percentage. Moreover, the RP and RF diets resulted in fat with better omega 3/omega 6 ratio compared with CTR. All the fat samples had iodine numbers within the limit value (70) reported by the Production Disciplinary of Parma ham. No treatment effect was found on the analytical and sensorial characteristics of the Parma hams, except for the aged taste which was more intense in the hams obtained from pigs fed the RF diet. These results indicate that pea and faba bean may be used as an alternative to imported SBM

Anticatabolic activity of alpha-ketoglutaric acid in growing rats

This study evaluated the anti-catabolic effect of α-ketoglutaric acid (AKG) in rats. Thirty Sprague Dowley male rats were divided into 3 groups of 10 animals each and fed ad libitum with protein-free diet (PFD) supplemented with 0, 3, and 6 g/kg feed of AKG for 14 consecutive days. The AKG administration had no effect on the growth performance of rats in the global trial period (0-14 d). After 7 d of excreta collection, the losses of endogenous nitrogen (N), both urinary and total, linearly reduced (P<0.05) following the administration of AKG, ranging from 35.00 mg/d to 28.00 mg/d, and from 45.28 mg/d to 36.36 mg/d, respectively. The villi and microvilli heights were lower when animals received 3 g/kg of AKG respecting to other tested AKG levels. Indeed, enterocytes length linearly increased (P<0.05) as the level of AKG increased in the diet by 25.0% (3 g/kg) and 49.0% (6 g/kg). The AKG levels quadratically influenced (P<0.05) the essential amino acids (EAA) concentrations in the blood, being EAA lower for animals treated with 6 g/kg of AKG (-21.6%) compared to the animals fed the control PFD and the PFD with 3 g/kg of AKG. In conclusion, AKG was effective in reducing catabolism and EAA depletion

Cell membrane lipid rafts mediate caveolar endocytosis of HIV-1 Tat fusion proteins.

The transactivator protein of human immunodeficiency virus type 1 Tat has the unique property of mediating the delivery of large protein cargoes into the cells when present in the extracellular milieu. Here we show that Tat fusion proteins are internalized by the cells through a temperature-dependent endocytic pathway that originates from cell membrane lipid rafts and follows caveolar endocytosis. These conclusions are supported by the study of the slow kinetics of the internalization of Tat endosomes, by their resistance to nonionic detergents, the colocalization of internalized Tat with markers of caveolar endocytosis, and the impairment of the internalization process by drugs that disrupt lipid rafts or disturb caveolar trafficking. These results are of interest for all those who exploit Tat as a vehicle for transcellular protein delivery

Redes de reciclagem de óleo de cozinha usado na macrometrópole de São Paulo

Objective: to analyze if the spatial distribution and the relationship of the main cooking oil waste collecting and processing companies in the Macrometropolis of Sao Paulo (MSP) support the characterization of their agglomeration as clusters or local productive arrangements (LPAs).Methodology: the research is of a qualitative nature with an exploratory approach based on multiple case studies involving three companies from a current universe of fifteen associated to The Brazilian Association for Awareness, Collection and Recycling of Edible Oil (ECOLEO) that congregates the most important companies active in this segment in MSP. It was based on bibliographical research, documentary survey and interviews followed by triangulation of information.Originality/Relevance: the analysis of the companies from the perspective of a cluster or a local productive arrangement allowed to verify how they are organized spatially in the MSP, as well as the relationship among them, aiming at suggesting governmental support for the optimization of its activities and the increase of income generation.Results: the research showed that the elements of the agglomeration´s economy identified were not sufficient to say that the segment could be characterized as either a cluster or a local productive arrangement. It was concluded that the companies studied have little interaction with each other, each forming an isolated network of cooperation with a number of small oil waste suppliers which gravitates around them.Theoretical Contributions: the contributions of the study highlights the identification of existing cooperation networks in the used cooking oil recycling segment and how its actors are organized and acting in MSP. It is also worth mentioning the expansion of the national literature on this theme that is an emerging one at the global level.Objetivo: analisar se a disposição espacial e o relacionamento entre as empresas coletoras e beneficiadoras de óleo de cozinha usado na Macrometrópole de São Paulo (MSP) permite caracterizá-las como clusters ou arranjos produtivos locais (APLs).Metodologia: a pesquisa é de natureza qualitativa com abordagem exploratória baseada em estudo de casos múltiplos envolvendo três empresas de um universo atual de quinze associadas à Associação Brasileira para Sensibilização, Coleta e Reciclagem de Óleo Comestível (ECÓLEO), que congrega as mais importantes empresas atuantes nesse segmento na MSP. Baseou-se em pesquisa bibliográfica, levantamento documental e entrevistas seguidas de triangulação das informações.Originalidade/Relevância: a análise das empresas sob a ótica de cluster ou arranjo produtivo, permitiu verificar como elas estão organizadas espacialmente na MSP, bem como o relacionamento entre elas, visando sugerir apoio governamental para a otimização de suas atividades e a ampliação da geração de renda.Resultados: a pesquisa mostrou que os elementos de economia de aglomeração identificados não se revelaram suficientes para dizer que o segmento se apresenta como cluster ou arranjo produtivo local. As empresas estudadas têm poucas interações entre elas formando redes isoladas de cooperação, compostas por pequenos fornecedores de óleo usado que gravitam em seus redores.Contribuições Teóricas: como contribuições do estudo destaca-se a identificação das redes de cooperação existentes no segmento de reciclagem de óleo de cozinha usado e de como os seus atores se organizam e atuam na MSP. Destaca-se também a ampliação da literatura nacional sobre essa temática que é emergente em nível mundial.Palavras-chave: Resíduo de óleo de cozinha. Clusters. Aglomerações. Arranjos produtivos locais – APLs. Redes de cooperaçã

Volatile constituents of Festuca nigrescens, Phleum alpinum and Poa alpina from N. W. Italian Alpine pastures.

The composition of the volatile fractions of three important grasses from subalpine N.W. Italian pastures, namely Festuca nigrescens Lam. non Gaudin (chewing fescue), Phleum alpinum L. (alpine timothy) and Poa alpina L. (alpine bluegrass) was investigated. The fresh aerial parts were collected at the flowering stage during the summer season. The volatile oils obtained from green tissues by steam distillation in a Clevenger-type apparatus, were analyzed by GC/FID and GC/MS. The oil yield was 0.04 ± 0.01% weight/fresh weight bases for each of the investigated species. Several classes of compounds were found in the volatile fractions, including aldehydes, alcohols, acids, hydrocarbons, esters, ketones, terpenes, and phenolics. Qualitative and quantitative differences were observed

Polyanionic Biopolymers for the Delivery of Pt(II) Cationic Antiproliferative Complexes

Phenanthriplatin, that is, (SP-4-3)-diamminechlorido(phenanthridine)platinum(II) nitrate, an effective antitumor cationic Pt(II) complex, was loaded on negatively charged dextran sulfate (DS) as a model vector for drug delivery via electrostatic interactions. The free complex and the corresponding conjugate with DS were tested on two standard human tumor cell lines, namely, ovarian A2780 and colon HCT 116, and on several malignant pleural mesothelioma cell lines (namely, epithelioid BR95, mixed/biphasic MG06, sarcomatoid MM98, and sarcomatoid cisplatin-resistant MM98R). The in vitro results suggest that the conjugate releases the active metabolite phenanthriplatin with a biphasic fashion. In these experimental conditions, the conjugate is slightly less active than free phenanthriplatin; but both exhibited antiproliferative potency higher than the reference metallodrug cisplatin and were able to overcome the acquired cisplatin chemoresistance in MM98R cells