1,393 research outputs found
Correction to: Combined botulinum toxin type A and electrical stimulation in individuals with C5-C6 and C6-C7 tetraplegia: a pilot study (Spinal Cord Series and Cases, (2020), 6, 1, (70), 10.1038/s41394-020-0317-2)
No full textThe original version of this Article contained an error in the spelling of the authors Francesco Piccione, Paolo Tonin, Antonio Cerasa and Stefano Masiero, which were incorrectly given as Piccione Francesco, Tonin Paolo, Cerasa Antonio, and Masiero Stefano, respectively. This has now been corrected in both the PDF and HTML versions of the Article
AN ENZYMATIC TOOL-BOX FOR LIGNIN OXIDATION/DEGRADATION
No full textLignin is an amorphous polymer characterized by a wide range of molecular mass components, a disordered and branched three-dimensional structure, insoluble in water and in most common solvents. In order to perform lignin degradation, enzymatic treatment could represent an environmentally friendly alternative to chemical methods[1].
The main purpose of this work was to develop an “enzymatic tool-box” for an efficient oxidation and degradation of lignin into aromatic monomers. Biochemical properties of a number of commercial and recombinant ligninolytic oxidative enzymes (laccases, Mn peroxidases and lignin peroxidases) were evaluated under identical experimental conditions, with the final goal to identify interesting biocatalysts for lignin degradation[2]. The effect of pH, temperature, NaCl, DMSO and Tween-80 on the enzymatic activity has been investigated. The activity of novel enzymes, such as the membrane-bound polyphenol oxidase from the marine bacterium Marinomonas mediterranea[3] and a peroxidase produced by Nonomuraea gerenzanensis, was also evaluated[4].
A new high-throughput colorimetric screening to assay the oxidation/degradation of lignin by different enzymes was developed: this method facilitates the identification of optimal conditions for a lignin treatment based on the combined use of various laccases and peroxidases[5]. On this side, coupling the colorimetric assay with a size-exclusion chromatography analysis allows to identify changes in lignin molecular mass distribution due to enzymatic treatment. Notably, the enzymatic tool-box also comprises etherases, cathecol oxidase and demethylase activities. Finally, a chemo-enzymatic process to depolymerise lignin was carried out on lignin linkage model compounds and technical lignins.
Altogether, the combination of chemical and enzymatic approaches could represent an innovative and feasible way for valorisation of lignin under mild conditions.
This work was done as part of Biorefill (ID42611813) and ValorPlus (no FP7-KBBE-2013-7-613802) projects.
[1] Pollegioni, L.; Tonin, F.; Rosini, E. FEBS Journal 2015, 282(7), 1190-1213.
[2] Tonin, F.; Melis, R.; Cordes, A.; Sanchez-Amat, A.; Pollegioni, L.; Rosini, E. New Biotechnology 2016,
33(3), 387-398.
[3] Tonin, F.; Rosini, E.; Piubelli, L.; Sanchez-Amat, A.; Pollegioni, L. Protein Expression and Purification
2016, (123), 60-69.
[4] Casciello, C.; Tonin, F.; Berini, F.; Fasoli, E.; Marinelli, F.; Pollegioni, L.; Rosini, E. Biotechnology Re- ports 2017, (13), 49-57.
[5] Tonin, F.; Vignali, E.; Pollegioni, L.; D’Arrigo, P.; Rosini, E. Enzyme and Microbial Technology 2017,
(96), 143-150
Cardiovascular and eletrocardiographic parameters after tonin administration in Wistar rats
No full textAbstractIn order to understand the mechanisms of interaction between tonin–angiotensin and renin–angiotensin systems (RAS) we evaluated, “in vivo” and “in vitro”, in Wistar rats, cardiovascular and electrocardiographic parameters after tonin administration. Arterial pressure (AP) and electrocardiogram (ECG) were recorded in awake animals before and after tonin administration. Langendorff technique was used to analyze cardiac function in isolated heart in the presence of tonin and video motion edge detection system was used to evaluate the effect of tonin upon contractile function of isolated rat ventricular cardiomyocytes. After tonin infusion rats presented significantly higher diastolic and mean arterial pressure (MAP) and heart rate (HR) as compared with control. The ECG analysis revealed shorter RR interval, increase in the low-frequency (LF) range of the heart rate variability (HRV) power (%) and decrease in the high-frequency (HF) of HRV power (%). Isolated hearts perfused with tonin presented an increase in the arterial coronary pressure (ACP) and decline in the ventricular systolic tension (ST), maximal (dT/dt+) and minimal (dT/dt) contractility. The rates of contraction and relaxation of isolated ventricular cardiomyocytes were significantly increased due to the presence of tonin. The angiotensin II (Ang II) levels in the coronary sinus effluent increased in the presence of tonin in a dose-dependent manner and the effect of tonin upon ACP was completely blocked by candesartan. Tonin is able to generate the vasoconstrictor peptide Ang II in the isolated heart of the rat and the cardiovascular response induced by tonin was completely blocked by candesartan, an indication that the action of Ang II on Ang II type 1 (AT1) receptors is the major mechanism of the heart effects. Tonin affects cardiomyocyte contractile function which may be due to interference with Ca2+ handling
Clinical and biochemical improvements in a patient with MNGIE following enzyme replacement.
No full textMitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive metabolic disorder caused by a deficiency of thymidine phosphorylase (TP, EC2.4.2.4) due to mutations in the nuclear gene TYMP. TP deficiency leads to plasma and tissue accumulations of thymidine and deoxyuridine which generate imbalances within the mitochondrial nucleotide pools, ultimately leading to mitochondrial dysfunction.1 MNGIE is characterized clinically by leukoencephalopathy, external ophthalmoplegia, peripheral polyneuropathy, cachexia, and enteric neuromyopathy manifesting as gastrointestinal dysmotility. The condition is relentlessly progressive, with patients usually dying from a combination of nutritional and neuromuscular failure at an average age of 37 years.2 Allogeneic hematopoietic stem cell transplantation (AHSCT) offers a permanent cure. Clinical and biochemical improvements following AHSCT have been reported but it carries a high mortality risk and is limited by matched donor availability.3 A consensus proposal for standardizing AHSCT recommends treatment of patients without irreversible end-stage disease and with an optimally matched donor; a majority of patients are ineligible and thus there is a critical requirement for an alternative treatment
Tonin expression in the rat brain and tonin-mediated central production of angiotensin II
No full textTonins are serine proteinases mainly found in the rat submandibular gland, which are capable of generating the pressor octapeptide angiotensin II (Ang II) not only from the classical substrate angiotensin I but also from the synthetic tetradecapeptide (AG(1 - 14)) and from angiotensinogen. in this work, tonin expression levels were evaluated in astrocytes and brain areas of the rat. By two different techniques (ribonuclease protection assay and reverse transcription - polymerase chain reaction), we could verify the presence of tonin mRNA in astrocytes and in the thalamus of the rat brain. Sequencing of the amplified brain cDNA determined it to be identical to that found in the submandibular gland. Central microinjection of tonin produced a transient (10-20 min) elevation of blood pressure and heart rate and induced water and saline intake within the first 10 min after injection. Urinary volume and salt excretion increased within 7 h after tonin injection. These effects were partially blocked by previously administered losartan, indicating that tonin effectively induced a central Ang II formation. Our data suggest that tonin may be an alternative pathway to Ang II generation in the brain and could participate in the physiological effects exerted by Ang II such as water and saline intake and blood pressure elevation. (C) 2002 Elsevier Science Inc. All rights reserved.Univ Fed Minas Gerais, Inst Biol Sci, Dept Physiol & Biophys, Belo Horizonte, MG, BrazilUniv Fed Minas Gerais, Sch Nursing, Belo Horizonte, MG, BrazilUniv Mogi Cruzes, São Paulo, BrazilMDC Mol Med, Berlin, GermanyUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilWeb of Scienc
Import tariffs enforcement with low administrative capacity
No full textImport tariff receipts represent an important share of government revenues in many developing countries and there has recently been a surge in empirical studies showing how evasion in this field is a pervasive phenomenon. In the case of import tariffs, the tax base is the product of quantity and unit value, both of which have to be reported and need to be assessed by the custom authority during an audit. I show that when the fiscal authority has an imperfect detection technology, there is an additional incentive for the taxpayer to underdeclare, as a greater declaration in one dimension actually increases the fine when evasion in the other dimension is detected, and a tax base presenting this feature is subject to more evasion compared to a tax base that can be assessed directly. Also, when enforcement capacity is low, voluntary compliance is higher when the importer is required to declare only the total value of import
The Effect of Proofreading on the Reading of General and Scientific Texts
No full textIzhodišča. V magistrski nalogi kvantitativno raziskujemo vpliv lekture na kakovost besedila, osredotočamo pa se predvsem na velikost učinka lekture na dojemanje različnih lastnosti besedila ob branju. Metodologija. Izvedli smo randomizirano enostransko slepo kvantitativno raziskavo z vprašalnikom, v kateri smo poskušali ustvariti čim bolj »naravno okolje« branja in v njem opredeliti učinek lektoriranja na dojemanje lastnosti izbranega publicističnega besedila. Za potrebe raziskave smo izdelali vprašalnik in izvedli predtestiranje. Za opis končnega vzorca smo uporabili deskriptivno statistiko. Pri spremenljivkah, ki smo jih obravnavali kot zvezne, smo izvedli t-test za dva neodvisna vzorca, pri analizi nominalnih spremenljivk pa test χ2. Za oceno velikosti učinka smo izračunali Cohenov d in razliko med povprečnimi vrednostmi. Vse proučevane lastnosti smo glede na analizo razdelili v razrede (zelo velik učinek, velik učinek, srednje velik učinek itd.). Upoštevali smo Bonferronijevo korekcijo, kot statistično značilne smo obravnavali rezultate s p < 0,00083. Rezultati. Celotna skupina je vsebovala 190 preiskovancev (dijake in študente medicine ter slovenistike), ki so rešili vprašalnik na sedmih ločenih anketnih testiranjih. Lektura je imela največji učinek na pravopisno ustreznost besedila (razlika 2,99 ± 0,210 točke na 7-stopenjski lestvici, Cohenov d = 2,07, 95-% IZ = 1,722,42, p < 0,0000). Prav tako je imela zelo velik učinek tudi na kakovost besedila pri analizi konstrukta 33 spremenljivk in na 7-stopenjski lestvici (razlika 1,81 ± 0,204 točke, Cohenov d = 1,29 95-% IZ = 0,971, 1,60p < 0,0000). Zelo velik učinek je imela na lastnosti, povezane z jezikovno pravilnostjo in predstavo o avtorju (njegovi izobrazbi in strokovnem ter jezikovnem znanju). Največ proučevanih lastnosti je spadalo v kategorijo s srednje velikim učinkom, le ena lastnost (količina podatkov v besedilu) pa je spadala v kategorijo z majhnim učinkom. Lektura ni vplivala na mnenje bralcev o tem, kje je bilo besedilo objavljeno, prav tako ne na predstavo bralca o recenziranosti besedila in na mnenje, ali je besedilo lektorirano ali ne. Razprava. Ugotovili smo, da ima lektura zelo velik učinek na kakovost besedila, jezikovno pravilnost besedila in predstavo o avtorju besedila, velik učinek na informativnost besedila in srednje velik učinek na zanimivost in znanstvenost. Raziskava odpira nove možnosti za osvetlitev področja.Introduction. We tried to quantify the effect of proofreading on the perception of a selected journalistic text. Methodology. We conducted a randomized one-sided blind quantitative survey with a questionnaire. Descriptive statistics were used to describe the final sample. For the analysis, we used the t-test for two independent samples and the χ2 test. For the standardised effect size estimation, we used Cohen\u27s d. We considered the Bonferroni correction, and the results were considered statistically significant with p < 0.00083. Results. The cohort consisted of 190 subjects (high school students and students of Medicine and Slovene Studies), who completed the questionnaire in seven separate administrations. Proofreading had the greatest effect on the orthographic adequacy of the text (difference of 2.99 ± 0.210 points on a 7-point scale, Cohen\u27s d = 2.07, 95% CI = 1.722.42, p < 0.0000). It also had a large effect on the quality of the text, and on the features related to linguistic correctness and perception of the author (his/her education, and professional and linguistic knowledge). Most of the characteristics studied belonged to the medium-effect category, while only one characteristic (the amount of information in the text) belonged to the low-effect category. Proofreading had a statistically insignificant effect on the readers’ perception of where the text was published, whether it was peer-reviewed, and whether it had been proofread or not. Discussion. We found that proofreading has a very large effect on the quality of the text, its linguistic correctness, and the perception of the author of the text, a large effect on the informativeness of the text, and a medium effect on the interestingness and the scientificity of the text. The research opens up new possibilities for shedding light on the field
Breaking lignin: blue and yellow laccases for a green chemistry
No full textLignin is an amorphous polymer with a molecular mass around 10 kDa that presents a three-dimensional structure disordered and branched, insoluble in water and most common solvents. During the industrial processes, lignin must be degraded and effectively removed. Enzymatic hydrolysis could be an environmentally friendly alternative to chemical methods to perform lignin degradation. The identification of enzymes able to efficiently fragmenting lignin, i.e., an "enzymatic tool box", is of utmost importance. On this side, laccase represents an enzymatic class of main relevance.
Laccases are attracting great scientific interest because of their very basic requirements and huge catalytic capabilities: this renders it one of the ‘‘greenest’’ enzymes [1].
In order to identify interesting lignin degrading biocatalysts, in this study we evaluated the main biochemical properties of a number of commercial and recombinant laccases under identical experimental conditions. The kinetic properties of laccases has been determined on 3 substrates: ABTS, catechol and 2,6-dimethoxyphenol (2,6-DMP). The microbial Bacillus licheniformis laccase (BALL) showed the highest specific activity and catalytic efficiency on ABTS, while the recombinant OB1 from Basidiomycete PM-1 showed the highest affinity for this compound [2]. The stability on pH, temperature, detergents and DMSO of the different laccases was also assessed.
Finally, a change in MW distribution after incubation of lignin with the laccase from Trametes versicolor was observed in gel permeation chromatography.
This work was done as part of the ValorPlus project that has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no FP7-KBBE-2013-7-613802.
[1] L. Pollegioni, F. Tonin, E. Rosini, FEBS J. 282 (7) (2015) 1190-1213
[2] F. Tonin, R. Melis, A. Cordes, A. Sanchez-Amat, L. Pollegioni, E. Rosini, Submitte
Role of the pituitary in the effects of tonin on adrenal secretion of the rat
No full text Chronically catheterized conscious rats were infused intravenously with tonin at 2.4 and 12 μg∙kg−1∙min−1 for 2 h. Plasma aldosterone concentration (PAC) at the end of the experiment was 11.2 ± 2.4 ng% in controls, 8.5 ± 2.8 ng% in rats infused with tonin at the lower rate, and 26.2 ± 3.6 ng% (p < 0.01 vs. controls) in rats infused at the higher rate. Plasma corticosterone (PC) was significantly higher (p < 0.05) in the group infused at the high rate while plasma renin activity (PRA) was significantly reduced in this group of rats. Plasma angiotensin II (AII) concentration was similar in all three groups. PAC was elevated after tonin infusion in the presence of AII blockade. PAC in conscious sodium-depleted rats infused with tonin was not significantly changed, but PRA was significantly reduced (p < 0.01). In chronically hypophysectomized rats, PAC remained unchanged by tonin infusion. The failure of tonin to stimulate aldosterone in hypophysectomized animals indicates a role of a pituitary hormone (probably ACTH) in the effect of tonin on adrenal secretion. </jats:p
Role of calcium and calmodulin in release of kallikrein and tonin from rat submandibular gland
No full text We investigated the role of calcium and calmodulin as intracellular mediators of kallikrein and tonin release induced by norepinephrine (NE). We studied the secretion rate of kallikrein and tonin from submandibular gland of rat in response to NE in the presence or absence of calcium, two calcium blockers, and four different calmodulin antagonists. Submandibular gland slices were incubated in vitro, and glandular kallikrein and tonin secreted into the incubation medium were determined by direct radioimmunoassays and expressed as nanograms per minute per milligram tissue. NE (10(-5) and 10(-4) M) increased the kallikrein secretion from the control value of 8.2 +/- 2.6 to 134.9 +/- 41.4 (P less than 0.05) and to 191.2 +/- 62.7 (P less than 0.05), and the release of tonin from a basal rate of 3.5 +/- 0.6 to 51.5 +/- 9.1 (P less than 0.05) and to 64.4 +/- 13.7 (P less than 0.05). The deletion of calcium and addition of EGTA into the incubation medium significantly attenuated the secretion of kallikrein and tonin induced by NE. Nifedipine, at concentrations which inhibit voltage-dependent calcium channels, did not affect the release of kallikrein and tonin, and only a high concentration (10(-4) M) reduced the release. TMB-8, a blocker of intracellular calcium, had no effect either. Phenothiazines, triflupromazine (10(-6) M) and trifluoperazine (10(-4) M), decreased significantly the kallikrein release elicited by 10(-5) M NE.(ABSTRACT TRUNCATED AT 250 WORDS) </jats:p
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