86 research outputs found

    Levulinic acid production from the green macroalgae chaetomorpha linum and valonia aegagropila harvested in the orbetello lagoon

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    In recent years, the replacement of fossil resources with renewable ones has received great interest, especially as regards the production of new valuable bio-products and bio-fuels, in order to replace the traditional petroleum-based ones. In this context, the exploitation of waste biomasses into added-value biochemicals is strongly encouraged. Among these ones, the algae ones are attracting considerable attention, in particular macroalgae which cause eutrophication problems in estuaries and lagoons, due to the drastic reduction of dissolved oxygen during their decomposition. This is true for Orbetello lagoon (Italy), where a large amount of algal biomasses is removed every year through an expensive practice, with consequent environmentally serious disposal problems. In this work, for the first time, the acid-catalyzed conversion of two different macroalgae harvested in Orbetello lagoon, Chaetomorpha linum (Muller) Kutzing and Valonia aegagropila C. Agardh, into levulinic acid was studied and optimized, adopting a one-pot hydrothermal treatment, under microwave heating and in the presence of aqueous diluted mineral acids, H2SO4 and HCl. Levulinic acid is a versatile platform chemical, classified by the United States Department of Energy as one of the top-12 promising bio-based building blocks. The effect of the main reaction parameters to give levulinic acid was investigated and discussed, in particular the type and concentration of the acid catalyst, the temperature and the reaction time. The highest levulinic acid yields of 19 wt% for Chaetomorpha linum and 16 wt% for Valonia aegagropila, calculated respect to the weight of the starting dried biomass, were reached. The achieved results are very promising and confirm the significant potential of these green algae as renewable starting feedstocks for levulinic acid production

    Tunable HMF hydrogenation to furan diols in a flow reactor using Ru/C as catalyst

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    5-hydroxymethylfurfural (HMF), accessible from various feedstocks, represents an important renewable platform-chemical, precursor for valuable biofuels and bio-based chemicals. In this work, the continuous hydrogenation of an aqueous solution of HMF to give strategic monomers, 2,5-bis(hydroxymethyl)furan (BHMF) and 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) was investigated in a continuous flow reactor adopting a commercial Ru/C (5 wt%) as catalyst. The influence of the main process variables on products yield and selectivity was studied and optimized. The highest BHMF and BHMTHF yields of 87.9 and 93.7 mol%, respectively, were achieved by tuning the catalyst contact time, keeping all other variables constant (temperature, pressure, hydrogen flow rate, initial HMF concentration). Intraparticle diffusion limitation for hydrogen and HMF was shown to occur at some of the tested conditions by performing the HMF hydrogenation with different catalyst particle sizes, confirmed by calculations. Constant catalyst activity was observed up to 6 h time-on-stream and then gradually reduced. Fresh and spent catalyst characterization showed no significant sintering and negligible leaching of ruthenium during time-on-stream. A decrease of the specific surface area was observed, mainly due to humin deposition which is likely the reason for catalyst deactivation. Catalyst performance could be restored to initial values by a thorough washing of the catalyst

    Blockade of EIF5A hypusination limits colorectal cancer growth by inhibiting MYC elongation

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    Eukaryotic Translation Initiation Factor 5A (EIF5A) is a translation factor regulated by hypusination, a unique posttranslational modification catalyzed by deoxyhypusine synthetase (DHPS) and deoxyhypusine hydroxylase (DOHH) starting from the polyamine spermidine. Emerging data are showing that hypusinated EIF5A regulates key cellular processes such as autophagy, senescence, polyamine homeostasis, energy metabolism, and plays a role in cancer. However, the effects of EIF5A inhibition in preclinical cancer models, the mechanism of action, and specific translational targets are still poorly understood. We show here that hypusinated EIF5A promotes growth of colorectal cancer (CRC) cells by directly regulating MYC biosynthesis at specific pausing motifs. Inhibition of EIF5A hypusination with the DHPS inhibitor GC7 or through lentiviral-mediated knockdown of DHPS or EIF5A reduces the growth of various CRC cells. Multiplex gene expression analysis reveals that inhibition of hypusination impairs the expression of transcripts regulated by MYC, suggesting the involvement of this oncogene in the observed effect. Indeed, we demonstrate that EIF5A regulates MYC elongation without affecting its mRNA content or protein stability, by alleviating ribosome stalling at five distinct pausing motifs in MYC CDS. Of note, we show that blockade of the hypusination axis elicits a remarkable growth inhibitory effect in preclinical models of CRC and significantly reduces the size of polyps in APCMin/+ mice, a model of human familial adenomatous polyposis (FAP). Together, these data illustrate an unprecedented mechanism, whereby the tumor-promoting properties of hypusinated EIF5A are linked to its ability to regulate MYC elongation and provide a rationale for the use of DHPS/EIF5A inhibitors in CRC therapy

    Balanços energético e econômico para produção de etanol a partir de batata-doce

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    The objective of this work was to assess the viability of sweet potato (Ipomoea batatas) for ethanol production, as well as to estimate the energy and budget balances for the crop. Data from the agricultural and industrial production phases were evaluated. Those from the agricultural phase were estimated from a field experiment and used for comparison of sweet potato genotypes. Those from the industrial phase were estimated based on the literature on the fossil fuel energy and electricity consumed in the ethanol production process. With average yields of 35 Mg ha-1 roots and 12 Mg ha-1 dry stems, the output/input ratios were 6.64 and 1.93 for the energy and budget balances, respectively. For yields of 50 and 80 Mg ha-1 roots (17 and 27 Mg ha-1 dry stems, respectively), the indexes for energy balance were 7.16 and 7.68, respectively, and those for energy budget were 2.76 and 4.42. The obtained results confirm the great aptitude of the sweet potato crop for biofuel production.O objetivo deste trabalho foi avaliar a viabilidade da batata-doce (Ipomoea batatas) para produção de etanol, bem como estimar os balanços energético e econômico para a cultura. Foram avaliados dados das fases agrícola e industrial de produção. Os da fase agrícola foram estimados a partir de experimento conduzido em campo e usados para comparação de genótipos de batata-doce. Os da fase industrial foram estimados com base na literatura sobre as energias fóssil e elétrica consumidas no processo de produção de etanol. Com a produção média de 35 Mg ha-1 de raízes e 12 Mg ha-1 de ramas secas, as razões entre rendimentos/investimentos foram de 6,64 e 1,93 para os balanços energético e econômico, respectivamente. Para as produtividades de 50 e 80 Mg ha-1 de raízes (17 e 27 Mg ha-1 de matéria seca de ramas, respectivamente), os índices de balanço energético foram 7,16 e 7,68, respectivamente, e os de balanço econômico, 2,76 e de 4,42. Os resultados obtidos confirmam a grande aptidão da cultura de batata-doce para produção de biocombustível

    Beneficial effects of physical activity in an HIV-infected woman with lipodystrophy: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Lipodystrophy is common in patients infected with human immunodeficiency virus receiving highly active antiretroviral therapy, and presents with morphologic changes and metabolic alterations that are associated with depressive behavior and reduced quality of life. We examined the effects of exercise training on morphological changes, lipid profile and quality of life in a woman with human immunodeficiency virus presenting with lipodystrophy.</p> <p>Case presentation</p> <p>A 31-year-old Latin-American Caucasian woman infected with human immunodeficiency virus participated in a 12-week progressive resistance exercise training program with an aerobic component. Her weight, height, skinfold thickness, body circumferences, femur and humerus diameter, blood lipid profile, maximal oxygen uptake volume, exercise duration, strength and quality of life were assessed pre-exercise and post-exercise training. After 12 weeks, she exhibited reductions in her total subcutaneous fat (18.5%), central subcutaneous fat (21.0%), peripheral subcutaneous fat (10.7%), waist circumference (WC) (4.5%), triglycerides (9.9%), total cholesterol (12.0%) and low-density lipoprotein cholesterol (8.6%). She had increased body mass (4.6%), body mass index (4.37%), humerus and femur diameter (3.0% and 2.3%, respectively), high-density lipoprotein cholesterol (16.7%), maximal oxygen uptake volume (33.3%), exercise duration (37.5%) and strength (65.5%). Quality of life measures improved mainly for psychological and physical measures, independence and social relationships.</p> <p>Conclusions</p> <p>These findings suggest that supervised progressive resistance exercise training is a safe and effective treatment for evolving morphologic and metabolic disorders in adults infected with HIV receiving highly active antiretroviral therapy, and improves their quality of life.</p

    GZMKhigh CD8+ T effector memory cells are associated with CD15high neutrophil abundance in non-metastatic colorectal tumors and predict poor clinical outcome.

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    CD8(+) T cells are a major prognostic determinant in solid tumors, including colorectal cancer (CRC). However, understanding how the interplay between different immune cells impacts on clinical outcome is still in its infancy. Here, we describe that the interaction of tumor infiltrating neutrophils expressing high levels of CD15 with CD8(+) T effector memory cells (T(EM)) correlates with tumor progression. Mechanistically, stromal cell-derived factor-1 (CXCL12/SDF-1) promotes the retention of neutrophils within tumors, increasing the crosstalk with CD8(+) T cells. As a consequence of the contact-mediated interaction with neutrophils, CD8(+) T cells are skewed to produce high levels of GZMK, which in turn decreases E-cadherin on the intestinal epithelium and favors tumor progression. Overall, our results highlight the emergence of GZMK(high) CD8(+) T(EM) in non-metastatic CRC tumors as a hallmark driven by the interaction with neutrophils, which could implement current patient stratification and be targeted by novel therapeutics

    Impact of Chronic Lung Disease on Very Low Birth Weight infants: a collaborative study of the Italian Group of Neonatal Pneumology

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    Objective. To evaluate the incidence and risk factors for chronic lung disease in a population of very low birth weight infants. Methods. In a prospective multicentric trial all very low birth weight infants (&lt; 1500 g) accepted in 36 Italian Neonatal Intensive care units were studied from February 89 to January 99. For each patient were recorded maternal history, perinatal events, respiratory disease, infections, patent ductus arteriosus, retinopathy of prematurity, intraventricular haemorrhage and final outcome. Logistic regression analysis was performed in a multivariate assessment of risk factors for chronic lung disease. Results. In the study were included 1634 patients: 1387 infants survived beyond 36 weeks and 6.9% of them still oxygen dependent. The incidence of chronic lung disease was higher among babies with a gestational age of &lt; 28 weeks and weight \ub2 1000 g. The multivariate analysis showed that low birth weight, respiratory distress syndrome, persistent ductus arteriosus and sepsis were the main risk factors. Conclusions. In our study the incidence of chronic lung disease was relatively lo

    Lack of Galectin-3 Drives Response to Paracoccidioides brasiliensis toward a Th2-Biased Immunity

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    There is recent evidence that galectin-3 participates in immunity to infections, mostly by tuning cytokine production. We studied the balance of Th1/Th2 responses to P. brasiliensis experimental infection in the absence of galectin-3. The intermediate resistance to the fungal infection presented by C57BL/6 mice, associated with the development of a mixed type of immunity, was replaced with susceptibility to infection and a Th2-polarized immune response, in galectin-3-deficient (gal3−/−) mice. Such a response was associated with defective inflammatory and delayed type hypersensitivity (DTH) reactions, high IL-4 and GATA-3 expression and low nitric oxide production in the organs of infected animals. Gal3−/− macrophages exhibited higher TLR2 transcript levels and IL-10 production compared to wild-type macrophages after stimulation with P. brasiliensis antigens. We hypothesize that, during an in vivo P. brasiliensis infection, galectin-3 exerts its tuning role on immunity by interfering with the generation of regulatory macrophages, thus hindering the consequent Th2-polarized type of response

    Comparison of IRES and F2A-Based Locus-Specific Multicistronic Expression in Stable Mouse Lines

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    Efficient and stoichiometric expression of genes concatenated by bi- or multi-cistronic vectors has become an invaluable tool not only in basic biology to track and visualize proteins in vivo, but also for vaccine development and in the clinics for gene therapy. To adequately compare, in vivo, the effectiveness of two of the currently popular co-expression strategies - the internal ribosome entry site (IRES) derived from the picornavirus and the 2A peptide from the foot-and-mouth disease virus (FDMV) (F2A), we analyzed two locus-specific knock-in mouse lines co-expressing SRY-box containing gene 9 (Sox9) and enhanced green fluorescent protein (EGFP) linked by the IRES (Sox9IRES-EGFP) or the F2A (Sox9F2A-EGFP) sequence. Both the constructs expressed Sox9 and EGFP proteins in the appropriate Sox9 expression domains, with the IRES construct expressing reduced levels of EGFP compared to that of the F2A. The latter, on the other hand, produced about 42.2% Sox9-EGFP fusion protein, reflecting an inefficient ribosome ‘skipping’ mechanism. To investigate if the discrepancy in the ‘skipping’ process was locus-dependent, we further analyzed the FLAG3-Bapx1F2A-EGFP mouse line and found similar levels of fusion protein being produced. To assess if EGFP was hindering the ‘skipping’ mechanism, we examined another mouse line co-expressing Bagpipe homeobox gene 1 homolog (Bapx1), Cre recombinase and EGFP (Bapx1F2A-Cre-F2A-EGFP). While the ‘skipping’ was highly efficient between Bapx1 and Cre, the ‘skipping’ between Cre and EGFP was highly inefficient. We have thus demonstrated in our comparison study that the efficient and close to equivalent expression of genes linked by F2A is achievable in stable mouse lines, but the EGFP reporter may cause undesirable inhibition of the ‘skipping’ at the F2A sequence. Hence, the use of other reporter genes should be explored when utilizing F2A peptides
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