289 research outputs found

    Nitrosative stress defences of the enterohepatic pathogenic bacterium Helicobacter pullorum

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    Helicobacter pullorum is an avian bacterium that causes gastroenteritis, intestinal bowel and hepatobiliary diseases in humans. Although H. pullorum has been shown to activate the mammalian innate immunity with release of nitric oxide (NO), the proteins that afford protection against NO and reactive nitrogen species (RNS) remain unknown. Here several protein candidates of H. pullorum, namely a truncated (TrHb) and a single domain haemoglobin (SdHb), and three peroxiredoxin-like proteins (Prx1, Prx2 and Prx3) were investigated. We report that the two haemoglobin genes are induced by RNS, and that SdHb confers resistance to nitrosative stress both in vitro and in macrophages. For peroxiredoxins, the prx2 and prx3 expression is enhanced by peroxynitrite and hydrogen peroxide, respectively. Mutation of prx1 does not alter the resistance to these stresses, while the single ∆prx2 and double ∆prx1∆prx2 mutants have decreased viability. To corroborate the physiological data, the biochemical analysis of the five recombinant enzymes was done, namely by stopped-flow spectrophotometry. It is shown that H. pullorum SdHb reacts with NO much more quickly than TrHb, and that the three Prxs react promptly with peroxynitrite, Prx3 displaying the highest reactivity. Altogether, the results unveil SdHb and Prx3 as major protective systems of H. pullorum against nitrosative stress

    Evolución de los hidrocarburos lineales saturados en el aceite de la pulpa de aguacate (Persea americana, Mill.) a diferentes estados de maduración.

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    The n-alkane composition of Avocado pulp oil (cv. Hass) was investigated during fruit ripening. Three samples of fruit were harvested on March 3, 2003, March 18, 2003 and April 2, 2003. Glass gravity column chromatography was employed to separate n-alkanes from other minor components contained in the unsaponifiable fraction. Gas chromatography was used to analyze the eluate. Fourteen compounds were detected ranging from n -C21 to n -C34; mainly n -C24, followed by n -C25 and then by n -C23. Quantities of n -C21, n -C22, n -C23, n -C27 and n -C28 progressively increased during ripening, whereas n -C24, n -C25, n -C26, n -C29, n -C30 and n -C34 decreased from the first harvest date to the third harvest date. While odd-numbered carbon n-alkanes increased (52.38 %, 52.85 % and 53.06 % for the three samples respectively), even-numbered carbon n-alkanes decreased as the fruit ripened (47.62 %, 47.15 % and 46.94 %). The total n-alkane content decreased during ripening, from 25.20 mg/Kg (first harvest date) to 16.77 mg/Kg (third harvest date). In order to minimize.Se ha analizado la composición en hidrocarburos lineales saturados del aceite de la pulpa de aguacate (variedad Hass). Tres muestras fueron recolectadas: el 3 de marzo 2003, el 18 de marzo 2003 y el 2 de abril 2003. La separación de los hidrocarburos lineales saturados se realizó mediante fraccionamiento del insaponificable por cromatografía gravimétrica de adsorción en columna y la determinación de los mismos hidrocarburos por cromatografía gaseosa. 14 compuestos fueron detectados del n- C21 al n- C34. El n- C24 fue el mayoritario, seguido del n- C25 y el n- C23. El porcentaje de n- C21, n- C22, n- C23, n- C27 y n- C28, aumentó durante la maduración, mientras que el porcentaje de n- C24, n- C25, n- C26, n- C29, n- C30 y C34 disminuyó desde el 3 de marzo 2003 hasta el 2 de abril 2003. Los hidrocarburos lineales saturados con número impar de átomos de carbono aumentaron (52.38 %, 52.85 % y 53.06 % por las tres muestras respectivamente) con la maduración. Por el contrario, hidrocarburos lineales saturados con número par de carbono disminuyeron (47.62 %, 47.15 % y 46.94 %). El contenido total en hidrocarburos lineales saturados disminuyó durante la maduración desde 25.20 mg/kg (3 de marzo 2003) hasta 16.77 mg/kg (2 de abril 2003). Para reducir el contenido total en hidrocarburos lineales saturados en el aceite de aguacate (variedad Hass) es necesario retardar la cosecha del fruto

    Efectos de la variedad y año de cosecha sobre la composición de alcoholes grasos de aceites de oliva del Suroeste de Calabria (Italia)

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    The fatty alcohol (FAL) composition of olive oils produced in Southwest Calabria (Southern Italy) was analyzed over three harvest years 2005–2006–2007. Three autochthonous cultivars: Cassanese, Ottobratica, Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine were considered. Hexacosanol was always the main FAL occurring in the olive oil. The autochthonous cultivars were among those with the highest total FAL contents. Nevertheless, both autochthonous and allochthonous cultivars produced olive oil within the limit indicated by EU and IOC regulations. Cultivar affected the FAL content highly significantly or very highly significantly, whereas in a large part of the cases the harvest year did not influence the FAL content. Cultivar x harvest year influenced highly significantly or very highly significantly only C22-OH, C23-OH, C24-OH, C25-OH, odd chain FALs and the ratio even chain/odd chain FALs.Se ha analizado, durante tres cosechas 2005–2006–2007, la composición de alcoholes grasos (FAL) de aceites de oliva producidos en el suroeste de Calabria (sur de Italia). Se consideraron tres cultivares autóctonos: Cassanese, Ottobratica y Sinopolese y siete alóctonas: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino y Picholine. Hexacosanol fue siempre el principal FAL en los aceites de oliva. Los cultivares autóctonos se encuentran entre los de mayor contenido total de FAL. No obstante, ambos cultivares, autóctonos y alóctonos producen aceites de oliva dentro de los límites de los reglamentos de la UE y del COI. Los cultivares afectan de manera altamente significativa o muy significativa al contenido de FAL, mientras que el año de cosecha no influyó en el contenido de FAL. Cultivar x año de cosecha influye de manera altamente significativa o muy significativa sobre C22-OH, C23-OH, C24-OH, C25-OH, al total de alcoholes grasos de cadena impar y a la relación: FALs cadena par/FALcadena impar

    Current Insights on Early Life Nutrition and Prevention of Allergy

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    The incidence of allergic diseases in childhood appears to have significantly increased over the last decades. Since environmental factors, including diet, have been thought to play a significant role in the development of these diseases, there is great interest in identifying prevention strategies related to early nutritional interventions. Breastfeeding is critical for the immune development of newborns and infants through immune-modulating properties and it impacts the establishment of a healthy gut microbiota. However, the evidence for a protective role of breastfeeding against the development of food allergy in childhood is controversial, and there is little evidence to support the benefits of an antigen avoidance diet during lactation. Although it is not possible to draw a definitive conclusion about the protective role of breast milk against allergic diseases, exclusive breastfeeding is still recommended throughout the first 6 months of life due to associated health benefits. Furthermore, recommendations regarding complementary feeding in infancy have been significantly modified over the last few decades. Several studies have shown that delayed exposure to allergenic foods does not have a role in allergy prevention and recent guidelines recommend against delaying the introduction of complementary foods after 6 months of age, both in high- and low-risk infants. However, trials investigating this dietary approach have reported equivocal results so far. This review summarizes the available high-quality evidence regarding the efficacy of the principal dietary interventions proposed in early life to prevent allergic diseases in children

    A Novel Type of Nitric-oxide Reductase ESCHERICHIA COLI FLAVORUBREDOXIN

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    Escherichia coli flavorubredoxin is a member of the family of the A-type flavoproteins, which are built by two core domains: a metallo-β-lactamase-like domain, at the N-terminal region, harboring a non-heme di-iron site, and a flavodoxin-like domain, containing one FMN moiety. The enzyme fromE. coli has an extra module at the C terminus, containing a rubredoxin-like center. The A-type flavoproteins are widespread among strict and facultative anaerobes, as deduced from the analysis of the complete prokaryotic genomes. In this report we showed that the recombinant enzyme purified from E. coli has nitric-oxide reductase activity with a turnover number of ∼15 mol of NO·mol enzyme−1·s−1, which was well within the range of those determined for the canonical hemeb3 -FeB containing nitric-oxide reductases (e.g. ∼10–50 mol NO·mol enzyme−1·s−1 for the Paracoccus denitrificans NOR). Furthermore, it was shown that the activity was due to the A-type flavoprotein core, as the rubredoxin domain alone exhibited no activity. Thus, a novel family of prokaryotic NO reductases, with a non-heme di-iron site as the catalytic center, was established

    Sulfolobus acidocaldarius terminal oxidase. A kinetic investigation and its structural interpretation.

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    Abstract The thermoacidophilic archaebacterium Sulfolobus acidocaldarius possesses a very unusual terminal oxidase. We report original kinetic experiments on membranes of this microorganism carried out by stopped flow, using time-resolved optical spectroscopy combined with singular value decomposition analysis. The reduced-oxidized kinetic difference spectrum of the Sulfolobus membranes is characterized by three significant peaks in the visible region at 605, 586, and 560 nm. The 605-nm peak and part of the 586-nm peak (cytochrome aa3-type quinol oxidase) are reduced synchronously by both ascorbate plus N,N,N',N'-tetramethyl-p-phenylendiamine (TMPD) and dithionite, and they are very rapidly oxidized by molecular oxygen. A second pool of cytochromes seems to contribute to the 586-nm peak which is not reduced by ascorbate plus TMPD and reacts very slowly with dithionite. The b-type cytochromes (560 nm peak) are reduced by both reductants and are essentially "non-autoxidizable" at room temperature. Only one CO binding site with spectral features, kinetic properties, and ligand affinity not very dissimilar from those of mammalian cytochrome oxidase can be detected in the ascorbate-reduced membranes. On the contrary, a second CO binding site having unusual properties for aa3 terminal oxidases can be detected in the dithionite-reduced membranes

    The burden of Candida species colonization in NICU patients: a colonization surveillance study

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    Fungal infections are an important cause of morbidity and mortality in neonatal intensive care units (NICUs). The identification of specific risk factors supports prevention of candidemia in neonates. Effective prophylactic strategies have recently become available, but the identification and adequate management of high-risk infants is still a priority. Prior colonization is a key risk factor for candidemia. For this reason, surveillance studies to monitor incidence, species distribution, and antifungal susceptibility profiles, are mandatory. Among 520 infants admitted to our NICU between January 2013 and December 2014, 472 (90.77%) were included in the study. Forty-eight out of 472 (10.17%) patients tested positive for Candida spp. (C.), at least on one occasion. All the colonized patients tested positive for the rectal swab, whereas 7 patients also tested positive for the nasal swab. Fifteen out of 472 patients (3.18%) had more than one positive rectal or nasal swab during their NICU stay. Moreover, 9 out of 15 patients tested negative at the first sampling, suggesting they acquired Candida spp. during their stay. Twenty-five of forty-eight (52.1%) colonized patients carried C.albicans and 15/48 (31.25%) C.parapsilosis. We identified as risk factors for Candida spp. colonization: antibiotic therapy, parenteral nutrition, the use of a central venous catheter, and nasogastric tube. Our experience suggests that effective microbiological surveillance can allow for implementing proper, effective and timely control measures in a highrisk setting

    Predictors of Hepatocellular Carcinoma Early Recurrence in Patients Treated with Surgical Resection or Ablation Treatment: A Single-Center Experience

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    Introduction: Hepatocellular carcinoma (HCC) is the sixth most diagnosed malignancy and the fourth leading cause of cancer-related death worldwide, with poor overall survival despite available curative treatments. One of the most crucial factors influencing survival in HCC is recurrence. The current study aims to determine factors associated with early recurrence of HCC in patients with BCLC Stage 0 or Stage A treated with surgical resection or local ablation. Materials and Methods: We retrospectively enrolled 58 consecutive patients diagnosed with HCC within BCLC Stage 0 or Stage A and treated either by surgical resection or local ablation with maximum nodule diameter 20 mm (HR 4.5, 95% C.I. 3.9–5.1), platelet count 2 (HR 2.7, 95% C.I. 2.2–3.3). Discussion and Conclusions: Our results are in line with the current literature. Male gender and tumor nodule dimension are the main risk factors associated with early HCC recurrence. Platelet count and other combined scores can be used as predictive tools for early HCC recurrence, although more studies are needed to define cut-offs

    Giacomo Serpotta e il "pareggiamento delle arti": la decorazione degli oratori fra manipolazione vitalistica e vocazione classicista

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    ABSTRACT GIACOMO SERPOTTA AND THE “EQUALIZATION OF THE ARTS”: DECORATION OF THE ORATORIES BETWEEN VITALISTIC MANIPULATION AND CLASSICIST VOCATION Ettore Sessa The value of the whole of Giacomo Serpotta's artistic vision in the orchestration of the figu¬rative apparatuses of his oratories was certainly one of the principal primers of his historical-critical raising in the modernist period. In 1901 Mauceri and in 1911 Ricci and Basile heighten a profile of it, however synthetic, of angling and above all of different breath from the rediscovery realized in positivist age. Classifiable, in fact, among the eighteenth century precedents of Gesamtkunstwerk aesthetical plant (according to a rather diffused custom within the artistic historiography of modernist culturaI area or of decadentist origin, as in different formalistic demonstrations of the wealthiest society Belle Époque) the progress of Serpottas artistic way towards tangible expressions of the idea of «the whole work of art» has a unmistakable im¬print of his and, at the same time, a feasibility thanks to the plasticism of gestures and to the uni¬tary multiplicity of his modeled. In his oratories arrangements the "realist" component, not exempted from hedonistic sensual witty remarks, acts on a foundation of Hellenic taste (also in the use of profiles and architectural elements). With wise modulation and with dosing diversified for intensity, according the nature of the subjects, combines history (see the «teatrini» with perspective sceneries, among which the Lepanto battle), micro history (from feminine allegorical subjects, to attractive dames modernly adorned with ends and brocades, to "picciotti" proudly ragged and to the anecdotal of the daily life), mysticism (from the devotional subjects to the allegories of the virtues), obscurity (from numerological components to philosophical attributes) and, finally, mythology (from the allegorical correspondences between Christianity and paganism to classical simbology). Despite the actual halving of this group of oratories (was destroyed by traumatic events as earthquakes and war actions, or by villainous demolitions big part of Serpottas works, among which the SS. Sacrament oratories to Kalsa and those of Saint Maria del Ponticello), the comparison among the palermitan examples reached us entire allows the individualization of the characters of originality typical of the generaI composition, over that of those figurative unanimously accredited among the most valid of the late- Baroque European sculpture. The typical scheme of these oratories, places with a strong secular imprint (predisposed as for cultural reunions how as for the preclusive congregational assemblies, to which the only ones not admitted affiliate were the artists), has as constants: the hall with a rectangular plant; the skiff or pavilion vault with plaster decorations dissimulating the constructive geometry; the sculptural wall register above of a high plinth; windows on the greatest sides (in number of three); two doors in the counterfacade, originally with desk for the assemblies in central position, below the principal devotional allegorical composition. The first oratory to which Giacomo Serpotta imposes an unitary imprint, except the cappellone only defined between 1717 and the following year) is that of SS. Rosary in S. Cita; he has worked since 1685 to 1688 on behalf of SS. Rosary Company. Serpotta is twenty nine, but already since almost ten years, after the apprenticeship with subordinate roles, he showed himself almost beginning in mute with the decorations of Madonna of the Pity church in Monreale, where he operated like Procopio De' Ferrari's collaborator, and perhaps with his interventions in 1678 in the lateral walls of S. Mercurio oratory, to which follow the 1679 decoration works in the Charity oratory in St. Bartholomeo of the Incurable people (no more existing), perhaps S. Pietro and S. Paolo statues dating back to 1680 for the greatest altar in Gancia church, the marble model for Charles H's equestrian monument for Messina (then realized in 1684) and during the two years 1683-1684 the scenic decorations for the transept altars of Carmine Maggiore church (where he collaborates with his brother Giuseppe and realizes the couples of twisted columns gilded and commented by a theory of plaster miniature scenes disposed according to a spiral development). Immediately after S. Cita oratory he realized, between 1688 and 1691, the decorative apparatuses of the Sacrament oratory in S. Nicolò to Kalsa (destroyed because of 1823 earthquake). Only eight years after the completion of this work (about which it was hypothesized that it were an advancement in comparison to the intervention in S. Cita) Giacomo Serpotta is entrusted by S. Francesco from Assisi and S. Lorenzo Companies to realize the complex allegorical and explanatory cycle of the plasters of S. Lorenzo orato¬ry. He worked partly on Giacomo Amato's sketches (to which are probably owed the reform interventions that confer to this oratory a great architectural "squaring" in comparison to others), completing the presbytery within 1706, while already from 1701 he is busy in the definition of the walls. In 1703 he began the counter facade with the monumental wall framework and high-relief representation of St. Lorenzo Martyrdom

    The Terminal Oxidase Cytochrome bd Promotes Sulfide-resistant Bacterial Respiration and Growth

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    Hydrogen sulfide (H2S) impairs mitochondrial respiration by potently inhibiting the heme-copper cytochrome c oxidase. Since many prokaryotes, including Escherichia (E.) coli, generate H2S and encounter high H2S levels particularly in the human gut, herein we tested whether bacteria can sustain sulfide-resistant O2-dependent respiration. E. coli has three respiratory oxidases, the cyanide-sensitive heme-copper bo3 enzyme and two bd oxidases much less sensitive to cyanide. Working on the isolated enzymes, we found that, whereas the bo3 oxidase is inhibited by sulfide with half-maximal inhibitory concentration IC50=1.1±0.1μM, under identical experimental conditions both bd oxidases are insensitive to sulfide up to 58μM. In E. coli respiratory mutants, both O2-consumption and aerobic growth proved to be severely impaired by sulfide when respiration was sustained by the bo3 oxidase alone, but unaffected by ≤200μM sulfide when either bd enzyme acted as the only terminal oxidase. Accordingly, wild-type E. coli showed sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases. In all tested conditions, cyanide mimicked the functional effect of sulfide on bacterial respiration. We conclude that bd oxidases promote sulfide-resistant O2- consumption and growth in E. coli and possibly other bacteria. The impact of this discovery is discussed
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