Atividade antileucêmica de chalconas sintéticas

Dissertação (mestrado) - Univesidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-graduação em FarmáciaAs chalconas são compostos intermediários essenciais na biossíntese dos flavonóides. São amplamente distribuídas no reino vegetal e encontradas em pequenas e grandes plantas. Muitos trabalhos demonstraram efeitos biológicos para as chalconas, incluindo efeito antiinflamatório, antioxidante, antimalárico e antitumoral. Diferentes substituintes nos anéis das chalconas podem resultar em compostos com diferentes atividades biológicas. O objetivo deste trabalho foi estudar a atividade antitumoral de dez chalconas derivadas quimicamente do 3,4-metilenodioxibenzaldeído nas células leucêmicas linfoblásticas L1210. Foram analisadas a viabilidade celular, o mecanismo de morte celular, as concentrações intracelulares de GSH e ATP e a toxicidade in vitro das chalconas em células progenitoras da medula óssea. Foi observado que as chalconas 5, 7 e 11 reduziram fortemente o número de células viáveis em 90.5 ± 1.2%, 87.1 ± 1.1% e 86.3 ± 2.2%, respectivamente, quando comparadas com o controle, e induziram a fragmentação do DNA na concentração de 100 µM. Dentre as dez chalconas testadas somente a 5, a 7 e a 11 apresentaram efeito citotóxico acentuado. A chalcona 5 mostrou o menor valor de IC50 em 24h e em 48h, nas concentrações de 45 e 22 µM, respectivamente. Os grupos metóxi que aumentam a densidade eletrônica do anel A, presentes nos compostos 5, 7, e 11, parecem aumentar sua citotoxicidade. A depleção de GSH mostrou-se proporcional à morte celular. As concentrações intracelulares de ATP foram esgotadas de maneira concentração-dependente, sugerindo que os compostos podem interferir no potencial de membrana mitocondrial e na síntese do ATP. A chalcona 7 foi o composto menos tóxico para células normais da medula óssea. Nossos resultados mostraram que as chalconas 5, 7 e 11 induziram à apoptose células L1210 e apresentam a chalcona 7 como a mais promissora para dar continuidade às investigações

ATP synthase complex from beef heart mitochondria. Role of the thiol group of the 25-kDa subunit of Fo in the coupling mechanism between Fo and F1.

In order to assess the role of thiol groups in the Fo part of the ATP synthase in the coupling mechanism of ATP synthase, we have treated isolated Fo, extracted from beef heart Complex V with urea, with thiol reagents, primarily with diazenedicarboxylic acid bis-(dimethylamide) (diamide) but also with Cd2+ and N-ethylmaleimide. FoF1 ATP synthase was reconstituted by adding isolated F1 and the oligomycin-sensitivity-conferring-protein (OSCP) to Fo. The efficiency of reconstitution was assessed by determining the sensitivity to oligomycin of the ATP hydrolytic activity of the reconstituted enzyme. Contrary to Cd2+, incubation of diamide with Fo, before the addition of F1 and OSCP, induced a severe loss of oligomycin sensitivity, due to an inhibited binding of F1 to Fo. This effect was reversed by dithiothreitol. Conversely, if F1 and OSCP were added to Fo before diamide, no effect could be detected. These results show that F1 (and/or OSCP) protects Fo thiols from diamide and are substantiated by the finding that the oligomycin sensitivity of ATP hydrolysis activity of isolated Complex V was also unaltered by diamide. Gel electrophoresis of FoF1 ATP synthase, reconstituted with diamide-treated Fo, revealed that the loss of oligomycin sensitivity was directly correlated with diminution of band Fo 1 (or subunit b). Concomitantly a band appeared of approximately twice the molecular weight of subunit Fo 1. As this protein contains only 1 cysteine residue (Walker, J. E., Runswick, M. J., and Poulter, L. (1987) J. Mol. Biol. 197, 89-100), the effect of diamide is attributed to the formation of a disulfide bridge between two of these subunits. These results offer further evidence for the proposal, based on aminoacid sequence and structural analysis, that subunit Fo 1 of mammalian Fo is involved in the binding with F1 (Walker et al. (1987]. N-Ethylmaleimide affects oligomycin sensitivity to a lesser extent than diamide, suggesting that the mode of action of these reagents (and the structural changes induced in Fo) is different

Analisi biostratifrafiche e paleoecologiche delle associazioni a nannofossili calcarei del Paleocene superiore-Eocene inferiore (Site U1409 Newfoundland Ridge, NW Atlantico).

This Master thesis aims to carry out biostratigraphic studies and analyse calcareous nannofossil assemblages from late Paleocene to early Eocene sediments recovered during IODP Expedition 342. In particular, the study material comes from Site 1409 (Hole A, B, C). During the preliminary phase of this investigation some contradictions arose from the relative positions detected for standard biohorizons in different Holes (B and C). We thus decided to spit our record by Holes to prove if these inconsistencies may be due to some mistakes in constructing mcd scale. In fact, this was the case and we eventually decided to propose an alternative depth, the proposed mcd (pmcd), to temporary overcome the problem. A medium to high resolution calcareous nannofossil biostratigraphy is provided that results in precise biostratigraphic classification of the studied interval at Site 1409. This stratigraphic succession expands from late Paleocene to early Eocene, that is from Zone NP9 to Zone NP13 in term of NP calcareous nannofossil zonation (Martini, 1971). A detailed analysis of biostratigraphic results evidenced also the presence of two hiati, the first positioned at the base of the Eocene and the second lying in the upper part of the studied section, between the upper part of Zone NP 12 and the lower part of Zone NP 13.ope

Sword and Words. Potere, linguaggio e retorica nella filosofia di Hobbes

The aim of this work is to propose a new interpretation of Hobbes’s philosophical system through the analysis of linguistic and rhetoric theory which is the leitmotif of the speculation of English thinker. The articulation of the six chapters of this contribution reflects the different angles of perspective with which I want to show the importance of the topic of language in the hobbesian thought and the annexed issues: first of all through a logic and scientific analysis, then in the epistemological and anthropological context; in the political, institutional and historical issue and finally through the theological question. The language is recognized as the Archimedean point of hobbesian thought and this highlights its performative role in the political and historical context. To this end, I want to analyze the issue of language in its dual and ambivalent appearance: on the one hand the linguistic instrument is primarily designed as the ratio essendi, the condition for the realization of the scientific universe and the creation of the political and legal world; on the other hand, its rhetorical use represents the leading cause of sedition and civil dissolution of the Commonwealth

Il carcinoma delle paratiroidi: impatto dello status genetico HRPT2 nella pratica clinica

ABSTRACT Background and aim of the study We looked for mutations of the HRPT2 gene, which encodes the parafibromin protein, and for its clinical impact in sporadic parathyroid carcinoma and atypical parathyroid adenoma because germ-line inactivating HRPT2 mutations have been found in a type of familial hyperparathyroidism - hyperparathyroidism-jaw tumor (HPT-JT) syndrome – that carries an increased risk of aggressive parathyroid cancer. Methods We investigated every patient with a diagnosis of parathyroid carcinoma or atypical parathyroid adenoma, who had undergone surgery by one surgeon from 1975 to May 2012 at our Department. Genetic studies were performed from genomic DNA isolated from peripheral blood leukocytes and parathyroid tissue. Preoperative (symptoms, biochemical analysis, imaging), operative (surgery, histological analysis) and post-operative (follow-up) data have been collected in a database and statistically processed. The genetic analysis results have been correlated with the clinical course. Results The study involved 70 patients (group 1: 39 carcinomas, group 2: 31 atypical adenoma). Until now, we investigated 18 patients with parathyroid carcinoma and 8 patients with atypical adenoma. We detected HRPT2 mutation in two patients with carcinoma that died for rapid tumor progression. Conclusions HRPT2 status would be a piece of information to add to the conventional clinical parameters: it correlates with a more aggressive disease. The diagnostic utility of the HRPT2 screening might provide grounds for more aggressive follow-up and family screening. This test will be especially helpful if it directs us to an aggressive surgical approach because that is ultimately the only cure for this devastating disease

The prion protein regulates glutamate-mediated Ca2+ entry and mitochondrial Ca2+ accumulation in neurons

The cellular prion protein (PrPC) whose conformational misfolding leads to the production of deadly prions, has a still-unclarified cellular function despite decades of intensive research. Following our recent finding that PrPC limits Ca2+ entry via store-operated Ca2+ channels in neurons, we investigated whether the protein could also control the activity of ionotropic glutamate receptors (iGluRs). To this end, we compared local Ca2+ movements in primary cerebellar granule neurons and cortical neurons transduced with genetically encoded Ca2+ probes and expressing, or not expressing, PrPC. Our investigation demonstrated that PrPC downregulates Ca2+ entry through each specific agonist-stimulated iGluR and after stimulation by glutamate. We found that, although PrP-knockout (KO) mitochondria were displaced from the plasma membrane, glutamate addition resulted in a higher mitochondrial Ca2+ uptake in PrP-KO neurons than in their PrPC-expressing counterpart. This was because the increased Ca2+ entry through iGluRs in PrP-KO neurons led to a parallel increase in Ca2+-induced Ca2+ release via ryanodine receptor channels. These data thus suggest that PrPC takes part in the cell apparatus controlling Ca2+ homeostasis, and that PrPC is involved in protecting neurons from toxic Ca2+ overloads

Effects of anisotropic and isotropic LIPSS on polymer filling flow and wettability of micro injection molded parts

In micro injection molding, the specific cavity surface texture and roughness directly influence the polymer flow and the heat transfer between polymer melt and mold. In this work, two different types of laser-induced periodic surface structures, linear and hexagonal, were generated, and their impact on the flow length in micro injection molding was evaluated. A complete investigation of the surface treatment effect on the polymer flow was carried out, comparing the performance of an untreated cavity surface with surfaces modified by LIPSS. The phenomenon was examined by localizing the weld lines created by the polymer flowing in two parallel channels having different surface treatments. Several cavity inserts were treated by varying the LIPSS process parameters to generate surfaces with different micro-and nanostructures directions and periodicity. Furthermore, the paper addresses the hydro-phobicity achieved on the micro molded surfaces replicated from mold inserts with different LIPSS-based surface topography. Mold surfaces with linear and hexagonal LIPSS and the respective molded parts were analyzed by optical profilometry and scanning electron microscopy to characterize the cavity surfaces replication and localize the weld lines on the micro injection molded parts

Partial uncoupling, or inhibition of electron transport rate, have equivalent effects on the relationship between the rate of ATP synthesis and proton-motive force in submitochondrial particles

AbstractThe rates of electron transport and of ATP synthesis have been measured in bovine heart Mg-ATP submito-chondrial particles oxidising succinate under conditions of partial attenuation of the proton-motive force by malonate or FCCP. This paper reports evidence that the relationship between the rate of ATP synthesis and the magnitude of the proton motive force is independent of the mode by which the decrease of the proton motive force is achieved

Célula a combustível microbiana: operação em diferentes tempos de detenção hidráulica e extração de energia ativa

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Ambiental, Florianópolis, 2022.As estações de tratamento de efluente (ETEs) são grandes consumidoras de energia elétrica no âmbito municipal. Ao mesmo tempo, as ETEs têm um potencial significativo de geração de energia devido à matéria orgânica ali presente. De modo a promover a sustentabilidade no processo, técnicas para recuperação deste conteúdo energético dos efluentes estão sendo desenvolvidas rapidamente. Por exemplo, células de combustível microbianas (CCM) têm sido amplamente estudadas como tecnologia para produzir eletricidade a partir de compostos orgânicos presentes nas águas residuárias. Como é uma tecnologia recente e em expansão, existem alguns obstáculos, como condições ótimas de operação, meios para utilizar a energia produzida, aumento da escala e aplicação em sistemas reais. No presente estudo, avaliou-se uma CCM de câmara única (CCM-U) de 2 L para tratamento de efluente sintético (simulando o efluente sanitário). A CCM-U foi inoculada e aclimatada com lodo anaeróbio operando em regime de batelada, atingindo estabilidade na tensão de 0,65 V e 74,60% de remoção da demanda química de oxigênio (DQO). Em seguida, operando em fluxo contínuo, três etapas com diferentes tempos de detenção hidráulica (TDH) foram executadas, sendo elas 12, 8 e 4 h, a fim de verificar o impacto no desempenho da CCM. Verificou-se que os valores máximos de geração de eletricidade e eficiência de tratamento foram obtidos em TDH de 12 h. A potência produzida pela CCM foi em média 52,04 ± 18,00 mW m-3 a uma corrente de 159,20 ± 26,30 mA m-3. Aproximadamente 20% da DQO foi removida com uma eficiência coulômbica de 5,44%. Além disso, o teste de toxicidade aguda com Lactuca sativa evidenciou efeitos tóxicos no efluente bruto. No entanto, não foi possível detectar o efeito tóxico do efluente da CCM operado a um TDH de 12 h, indicando o potencial da CCM em reduzir a toxicidade. A operação da CCM com resistor externo (CCM-R) não proporciona aproveitamento de energia, uma vez que a mesma é dissipada na forma de calor. Dessa forma, a CCM foi operada com extração de energia ativa (CCM-E). O sistema funcionou em ponto de potência máxima e permitiu o carregamento de uma bateria. Comparado com CCM-R, o sistema de captação de energia ativa (CCM-E) aumentou a potência e eficiência coulômbica em aproximadamente 2,5 e 2,4 vezes, respectivamente. O filo predominante no biofilme anódico foi Proteobacteria, Chloroflexi, Bacteroidetes e Firmicutes. A família Clostridiceae representa os organismos eletroativos no biofilme anódico. A toxicidade do efluente de CCM foi avaliada utilizando o ensaio com Daphnia Magna. Foi possível verificar que o efluente tratado pela CCM-R e CCM-E promoveu redução na toxicidade do efluente. Esses resultados demonstraram que a CCM-E, abastecida em fluxo contínuo apresenta potencial para atuar na remoção de poluentes e recuperação de energia em ETEs. Como pós-tratamento, sugere-se a integração da CCM-E com um eletrobiorreator a membrana (EBRM). A energia produzida e armazenada poderá ser aplicada no EMBR para atuar no pós-tratamento do efluente da CCM.Abstract: Wastewater treatment plants (WWTPs) are significant energy consumers at the municipal level. Meanwhile, WWTPs have considerable potential for sustainable energy recovery due to their intrinsic energy content. In order to promote sustainability in the process, techniques for recovering the energy content of wastewater are developing rapidly. For example, microbial fuel cells (MFCs) have been widely studied as potential devices to produce electricity from organic compounds in wastewater. As a novelty technology, there are some bottlenecks, such as gaps under optimal operational conditions, generation of practically usable power, scaled-up, and application in practical systems. In the present study, we assessed a scale-up single chamber MFC (2 L) for treating synthetic wastewater (similar to sewage). The MFC was successfully inoculated and acclimated with anaerobic sludge. The voltage reached a plateau of around 0.650 V and 74.60% COD removal under batch mode. After that, in a continuous flow, three sets of experiments with different combinations of hydraulic retention times (HRT), 12, 8, and 4 h, were performed to verify the impact on the MFC performance. It was found that electricity generation and wastewater treatment could be enhanced under an HRT of 12 h. The power produced by the MFC averaged 52.04 ± 18.00 mW m-3 at a current of 159.20 ± 26.30 mA m-3. Approximately 20% of the chemical oxygen demand (COD) was removed with a Coulombic efficiency of 5.44%. Furthermore, testing of acute toxicity with Lactuca sativa revealed toxic effects of the raw wastewater. However, it was not possible to detect the toxic effect of the effluent from the MFC operating under 12h HRT, indicating the potential to reduce toxicity. The operation with an external resistor does not provide energy use since it was dissipated as heat. Then, the MFC was operated with active energy harvesting (MFC-H). The system worked under maximal power point and enabled charging of a battery. Compared with the MFC-H, the active harvesting system increases power generation and Coulombic efficiency approximately 2.5 and 2.4 times, respectively. The predominant phylum at anode biofilm was Proteobacteria, Chloroflexi, Bacteroidetes, and Firmicutes. The Clostridiceae family might represent the electroactive organisms in the anodic biofilm. The toxicity of MFC effluent was evaluated using bioassay with Daphnia Magna. It is possible to verify that the effluent treated by MFC under resistor and active harvesting scenarios promoted a reduction in wastewater toxicity. Indeed, post-treatment is indicated to provide complete pollutant removal. These outcomes demonstrated that scaled-up MFC fed in continuous flow mode with synthetic wastewater should be an effective system for pollutant removal and energy recovery for wastewater treatment plants. As a post-treatment, it is suggested to integrate the MFC-H with an electro-membrane bioreactor (EMBR). The energy produced and stored could be applied in EMBR to treat the MFC effluent further