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1.
Bioconjug Chem ; 35(3): 324-332, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38366964

RESUMEN

Immunoconjugates exploit the high affinity of monoclonal antibodies for a recognized antigen to selectively deliver a cytotoxic payload, such as drugs or radioactive nuclides, at the site of disease. Despite numerous techniques have been recently developed for site-selective bioconjugations of protein structures, reaction of ε-amine group of lysine residues with electrophilic reactants, such as activated esters (NHS), is the main method reported in the literature as it maintains proteins in their native conformation. Since antibodies hold a high number of lysine residues, a heterogeneous mixture of conjugates will be generated, which can result in decreased target affinity. Here, we report an intradomain regioselective bioconjugation between the monoclonal antibody Trastuzumab and the N-hydroxysuccinimide ester of the chelator 2,2',2″,2‴-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA) by a kinetically controlled reaction adding substoichiometric quantities of the activated ester to the mAb working at slightly basic pH. Liquid chromatography-mass spectrometry (LC-MS) analyses were carried out to assess the chelator-antibody ratio (CAR) and the number of chelating moieties linked to the mAb chains. Proteolysis experiments showed four lysine residues mainly involved in bioconjugation (K188 for the light chain and K30, K293, and K417 for the heavy chain), each of which was located in a different domain. Since the displayed intradomain regioselectivity, a domain mapping MS-workflow, based on a selective domain denaturation, was developed to quantify the percentage of chelator linked to each mAb domain. The resulting immunoconjugate mixture showed an average CAR of 0.9. About a third of the heavy chains were found as monoconjugated, whereas conjugation of the chelator in the light chain was negligible. Domain mapping showed the CH3 domain bearing 13% of conjugated DOTA, followed by CH2 and VH respectively bearing 12.5 and 11% of bonded chelator. Bioconjugation was not found in the CH1 domain, whereas for the light chain, only the CL domain was conjugated (6%). Data analysis based on LC-MS quantification of different analytical levels (intact, reduced chains, and domains) provided the immunoconjugate formulation. A mixture of immunoconjugates restricted to 15 species was obtained, and the percentage of each one within the mixture was calculated. In particular, species bearing 1 DOTA with a relative abundance ranging from 4 to 20-fold, in comparison to species bearing 2DOTA, were observed. Pairing of bioconjugation under kinetic control with the developed domain mapping MS-workflow could raise the standard of chemical quality for immunoconjugates obtained with commercially available reactants.


Asunto(s)
Inmunoconjugados , Inmunoconjugados/química , Lisina/química , Flujo de Trabajo , Anticuerpos Monoclonales/química , Quelantes , Ésteres
2.
Antioxidants (Basel) ; 12(6)2023 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-37372042

RESUMEN

The beneficial effects of sardine consumption can be related to the presence of bioactive compounds, such as vitamin E and ω3 polyunsaturated fatty acids. In any case, the levels of these compounds in sardine fillet depend on different factors mainly related to the diet and reproductive cycle phase of the fish as well as the technological treatments carried out to cook the fillets. The aim of the present study is two-fold: first, to evaluate changes in the total fatty acid profile, lipid oxidation, and vitamin E content of raw fillets from sardine (Sardina pilchardus) at different reproductive cycle phases (pre-spawning, spawning, and post-spawning); and second, to highlight how these nutritional profiles are affected by three oven treatments (conventional, steam, and sous-vide). For this purpose, raw fish was grouped into pre-spawning, spawning, and post-spawning phases according to the mesenteric fat frequency and the gonadosomatic index evaluation, and submitted to conventional (CO), steam (SO), and sous-vide (SV) baking. The ratio of EPA/DHA and vitamin E increased from post-spawning to pre-spawning, to spawning. Considering the reproductive phases, baking affected the oxidative degree differently: a CO > SO ≥ SV impact was found in the worst scenario (post-spawning), mitigated by vitamin E, to CO ≥ SO > SV in the best scenario (spawning). SV was the best treatment with high values of vitamin E in pre-spawning individuals (110.1 mg/kg). This study shows how vitamin E is correlated to the combined effect of endogenous and exogenous factors.

3.
ACS Chem Neurosci ; 14(6): 1126-1136, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36857606

RESUMEN

Alzheimer's disease (AD) is the most common cause of dementia, characterized by a spectrum of symptoms associated with memory loss and cognitive decline with deleterious consequences in everyday life. The lack of specific drugs for the treatment and/or prevention of this pathology makes AD an ever-increasing economic and social emergency. Oligomeric species of amyloid-beta (Aß) are recognized as the primary cause responsible for synaptic dysfunction and neuronal degeneration, playing a crucial role in the onset of the pathology. Several studies have been focusing on the use of small molecules and peptides targeting oligomeric species to prevent Aß aggregation and toxicity. Among them, peptide fragments derived from the primary sequence of Aß have also been used to exploit any eventual recognition abilities toward the full-length Aß parent peptide. Here, we test the Aß8-20 fragment which contains the self-recognizing Lys-Leu-Val-Phe-Phe sequence and lacks Arg 5 and Asp 7 and the main part of the C-terminus, key points involved in the aggregation pathway and stabilization of the fibrillary structure of Aß. In particular, by combining chemical and biological techniques, we show that Aß8-20 does not undergo random coil to ß sheet conformational transition, does not form amyloid fibrils by itself, and is not toxic for neuronal cells. Moreover, we demonstrate that Aß8-20 mainly interacts with the 4-11 region of Aß1-42 and inhibits the formation of toxic oligomeric species and Aß fibrils. Finally, our data show that Aß8-20 protects neuron-like cells from Aß1-42 oligomer toxicity. We propose Aß8-20 as a promising drug candidate for the treatment of AD.


Asunto(s)
Enfermedad de Alzheimer , Fármacos Neuroprotectores , Humanos , Enfermedad de Alzheimer/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Péptidos beta-Amiloides/metabolismo , Fragmentos de Péptidos/metabolismo , Amiloide/metabolismo
4.
Front Microbiol ; 14: 1066406, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36819055

RESUMEN

Introduction: Continental hydrothermal systems (CHSs) are geochemically complex, and they support microbial communities that vary across substrates. However, our understanding of these variations across the complete range of substrates in CHS is limited because many previous studies have focused predominantly on aqueous settings. Methods: Here we used metagenomes in the context of their environmental geochemistry to investigate the ecology of different substrates (i.e., water, mud and fumarolic deposits) from Solfatara and Pisciarelli. Results and Discussion: Results indicate that both locations are lithologically similar with distinct fluid geochemistry. In particular, all substrates from Solfatara have similar chemistry whereas Pisciarelli substrates have varying chemistry; with water and mud from bubbling pools exhibiting high SO4 2- and NH4 + concentrations. Species alpha diversity was found to be different between locations but not across substrates, and pH was shown to be the most important driver of both diversity and microbial community composition. Based on cluster analysis, microbial community structure differed significantly between Pisciarelli substrates but not between Solfatara substrates. Pisciarelli mud pools, were dominated by (hyper)thermophilic archaea, and on average, bacteria dominated Pisciarelli fumarolic deposits and all investigated Solfatara environments. Carbon fixation and sulfur oxidation were the most important metabolic pathways fueled by volcanic outgassing at both locations. Together, results demonstrate that ecological differences across substrates are not a widespread phenomenon but specific to the system. Therefore, this study demonstrates the importance of analyzing different substrates of a CHS to understand the full range of microbial ecology to avoid biased ecological assessments.

5.
Foods ; 11(19)2022 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-36230116

RESUMEN

The impact of mild oven treatments (steaming or sous-vide) and boiling for 10 min, 25 min, or 40 min on health-promoting phytochemicals in orange and violet cauliflower (Brassica oleracea L. var. botrytis) was investigated. For this purpose, targeted ultra-high performance liquid chromatography-high-resolution mass spectrometry analysis of phenolics and glycosylates, combined with chemometrics, was employed. Regardless of cooking time, clear differentiation of cooked samples obtained using different procedures was achieved, thus demonstrating the distinct impact of cooking approaches on sample phytochemical profile (both, compound distribution and content). The main responsible components for the observed discrimination were derivatives of hydroxycinnamic acid and kaempferol, organic acids, indolic, and aromatic glucosinolates, with glucosativin that was found, for the first time, as a discriminant chemical descriptor in colored cauliflower submitted to steaming and sous-vide. The obtained findings also highlighted a strict relationship between the impact of the cooking technique used and the type of cauliflower. The boiling process significantly affected the phytochemicals in violet cauliflower whereas orange cauliflower boiled samples were grouped between raw and either steamed or sous-vide-cooked samples. Finally, the results confirm that the proposed methodology is capable of discriminating cauliflower samples based on their phytochemical profiles and identifying the cooking procedure able to preserve bioactive constituents.

6.
Front Endocrinol (Lausanne) ; 13: 940040, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36157439

RESUMEN

There is growing interest in the relationship between chronic kidney disease (CKD) and fragility fracture risk. Bone mineral density (BMD) is a major determinant of bone strength, although its role as a predictor of fracture in advanced CKD and hemodialysis is still under debate. We aimed to further investigate surrogates of bone quality and their associations with muscle strength and fracture risk in hemodialysis. Multiple clinical risk factors for fracture and an estimated 10-year probability of fracture, BMD at lumbar spine and femur, trabecular bone score (TBS), X-ray vertebral morphometry, phalangeal bone quantitative ultrasonography (QUS), tibial pulse-echo ultrasonography (PEUS), and handgrip strength were evaluated in a setting of hemodialysis patients in treatment with acetate-free biofiltration (AFB) or bicarbonate hemodialysis. The bone ultrasound measurements, both at phalangeal and tibial sites, were significantly associated with lumbar and femoral DXA values. Handgrip strength was significantly associated with the 10-year probability of fracture (r = -0.57, p < 0.001 for major fractures and r = -0.53, p < 0.001 for hip fracture, respectively), with femur neck, total femur, and L1-L4 BMD values (r = 0.47, p = 0.04; r = 0.48, p = 0.02; r = 0.58, p = 0.007, respectively), with TBS at the lumbar spine (r = 0.71, p < 0.001) and with the phalangeal QUS measure of AD-SoS (r = 0.369, p = 0.023). In the hemodialysis group, 10 participants (24.3%) reported at least one morphometric vertebral fracture (Vfx); conversely, only six participants (15%) showed Vfx in the control group. In the hemodialysis group, participants with Vfx compared with participants without Vfx reported significantly different TBS, bone transmission time (BTT), cortical thickness, and handgrip strength (p < 0.05). At multiple regression analysis, by identifying as dependent variable the 10-year fracture risk for major fracture, after correcting for age, BMI, time since dialysis, AD-SoS, cortical bone thickness, and handgrip strength, only BTT (ß = -15.21, SE = 5.91, p = 0.02) and TBS (ß = -54.69, SE = 21.88, p = 0.02) turned out as independently associated with fracture risk. In conclusion, hemodialysis patients showed a higher fracture risk and lower surrogate indices of bone strength as TBS and QUS parameters. In this cohort of patients, handgrip strength measurements appeared to be a useful instrument to identify high-fracture-risk subjects.


Asunto(s)
Fracturas Óseas , Insuficiencia Renal Crónica , Bicarbonatos , Densidad Ósea/fisiología , Hueso Esponjoso , Fracturas Óseas/diagnóstico por imagen , Fracturas Óseas/etiología , Fuerza de la Mano , Humanos , Vértebras Lumbares/diagnóstico por imagen , Fuerza Muscular , Diálisis Renal/efectos adversos , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/terapia , Ultrasonografía
7.
Molecules ; 27(16)2022 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-36014310

RESUMEN

In the last two decades, the amyloid hypothesis, i.e., the abnormal accumulation of toxic Aß assemblies in the brain, has been considered the mainstream concept sustaining research in Alzheimer's Disease (AD). However, the course of cognitive decline and AD development better correlates with tau accumulation rather than amyloid peptide deposition. Moreover, all clinical trials of amyloid-targeting drug candidates have been unsuccessful, implicitly suggesting that the amyloid hypothesis needs significant amendments. Accumulating evidence supports the existence of a series of potentially dangerous relationships between Aß oligomeric species and tau protein in AD. However, the molecular determinants underlying pathogenic Aß/tau cross interactions are not fully understood. Here, we discuss the common features of Aß and tau molecules, with special emphasis on: (i) the critical role played by metal dyshomeostasis in promoting both Aß and tau aggregation and oxidative stress, in AD; (ii) the effects of lipid membranes on Aß and tau (co)-aggregation at the membrane interface; (iii) the potential of small peptide-based inhibitors of Aß and tau misfolding as therapeutic tools in AD. Although the molecular mechanism underlying the direct Aß/tau interaction remains largely unknown, the arguments discussed in this review may help reinforcing the current view of a synergistic Aß/tau molecular crosstalk in AD and stimulate further research to mechanism elucidation and next-generation AD therapeutics.


Asunto(s)
Enfermedad de Alzheimer , Amiloidosis , Enfermedad de Alzheimer/metabolismo , Amiloide , Péptidos beta-Amiloides/metabolismo , Proteínas Amiloidogénicas , Humanos , Iones , Lípidos/uso terapéutico , Metales , Proteínas tau/metabolismo
8.
J Colloid Interface Sci ; 613: 814-826, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35074707

RESUMEN

Recognition and capture of amyloid beta (Aß) is a challenging task for the early diagnosis of neurodegenerative disorders, such as Alzheimer's disease. Here, we report a novel KLVFF-modified nanomagnet based on magnetic nanoparticles (MNP) covered with a non-ionic amphiphilic ß-cyclodextrin (SC16OH) and decorated with KLVFF oligopeptide for the self-recognition of the homologous amino-acids sequence of Aß to collect Aß (1-42) peptide from aqueous samples. MNP@SC16OH and MNP@SC16OH/Ada-Pep nanoassemblies were fully characterized by complementary techniques both as solid powders and in aqueous dispersions. Single domain MNP@SC16OH/Ada-Pep nanomagnets of 20-40 nm were observed by TEM analysis. DLS and ζ-potential measurements revealed that MNP@SC16OH nanoassemblies owned in aqueous dispersion a hydrodynamic radius of about 150 nm, which was unaffected by Ada-Pep decoration, while the negative ζ-potential of MNP@SC16OH (-40 mV) became less negative (-30 mV) in MNP@SC16OH/Ada-Pep, confirming the exposition of positively charged KLVFF on nanomagnets surface. The ability of MNP@SC16OH/Ada-Pep to recruit Aß (1-42) in aqueous solution was evaluated by MALDI-TOF and compared with the ineffectiveness of undecorated MNP@SC16OH and VFLKF scrambled peptide-decorated nanoassemblies (MNP@SC16OH/Ada-scPep), pointing out the selectivity of KLVFF-decorated nanohybrid towards Aß (1-42). Finally, the property of nanomagnets to extract Aß in conditioned medium of cells over-producing Aß peptides was investigated as proof of concept of effectiveness of these nanomaterials as potential diagnostic tools.


Asunto(s)
Péptidos beta-Amiloides , Ciclodextrinas , Oligopéptidos , Fragmentos de Péptidos
9.
Foods ; 10(9)2021 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-34574079

RESUMEN

The effects induced by heat on Depurple and Cheddar (Brassica oleracea L. var. botrytis) during boiling, steaming, and sous-vide were investigated to elucidate the role of the basic cellular elements in softening and extractability of sterols and tocopherols. With this aim, an elastoplastic mechanical model was conceptualized at a cell scale-size and validated under creep experiments. The total amount of the phytochemicals was used to validate multivariate regression models in forecasting. Boiling was the most effective method to enhance the softening mechanisms causing tissue decompartmentalization through cell wall loosening with respect to those causing cell separation, having no impact on the phytochemical extractability. Sous-vide showed the lowest impact on cell wall integrity, but the highest in terms of cell separation. Steaming showed an intermediate behavior. Tissue of the Depurple cauliflower was the most resistant to the heat, irrespectively to the heating technology. Local heterogeneity in the cell wall and cell membrane, expected as a plant variety-dependent functional property, was proposed as a possible explanation because sterol extractability under lower heat-transfer efficiency, i.e., steaming and sous-vide, decreased in Depurple and increased in Cheddar as well as because the extractability of sterols and tocopherols was greater in Cheddar.

10.
World J Surg ; 45(11): 3449-3457, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34370057

RESUMEN

BACKGROUND: Adult, benign, non-iatrogenic bronchoesophageal fistula (BEF) is a rare condition, which is occasionally described in single case reports. Therefore, little is known about its possible causes, presentation and management. METHODS: A systematic search of the literature in MEDLINE, PubMed Central and EMBASE databases between 1990 and 2020 was carried out to identify all cases of BEF. The initial database search identified 19,452 articles, of which 183 (251 individual patient cases) were included in the final analysis. RESULTS: Main causes of BEF were congenital malformations (97/251, 38.7%) and infections (82/251, 32.7%), while 33/251 (13.1%) fistulae were regarded as idiopathic and 39/251 (15.5%) attributed to other causes. Esophagograpy was the most sensitive method of diagnosis (97.4%) compared with esophagoscopy (78.9%), computed tomography (49.6%) and bronchoscopy (46.0%). Definitive treatment was surgical for 176 patients (70%), endoscopic for 25 (10%) and medical for 37 (14.7%). Compared with congenital BEFs, infective BEFs had shorter median symptom duration and were distributed more proximally over the bronchial tree. Definitive treatment was almost only surgical for congenital BEFs, while infective BEFs were treated also endoscopically (12%) and by medical therapy (38%). Morbidity, treatment failure and recurrence rates were higher for infective BEFs. CONCLUSIONS: BEFs are rare. Symptoms are non-specific and a high index of suspicion is necessary for diagnosis. Patients with infective BEF tend to have a more severe clinical picture than those with congenital BEF. Surgery is the main treatment for patients affected by congenital BEF, while infective BEFs may heal conservatively.


Asunto(s)
Fístula Bronquial , Fístula Esofágica , Adulto , Fístula Bronquial/etiología , Broncoscopía , Fístula Esofágica/etiología , Esofagoscopía , Humanos , Recurrencia
11.
Chemosphere ; 274: 129955, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33979924

RESUMEN

In the last decades, investigating geochemistry of sea sediments has been challenging in the eastern sector of Pozzuoli Bay, source of the metal(loid)s has been a matter of debate and the proposed origin of potentially toxic elements (PTEs) has been occasionally inconsistent. In this study, compositional data analysis (CoDA) was used because the results are independent of the measurement unit, the selected subgroup of elements and the order of chemicals in the dataset. The robust variant of principal component analysis (PCA) indicated that Hg, Cd, Cu, Pb and Zn were positively correlated with mud and organic matter in the sediments deposited in front of the former industrial site. Concentrations of these metals decrease along the cores and in the distal zone. Nevertheless, Al, As, V, Fe, Cr, Ni and sand form an association along the coast which strengthens with increasing distance from fumaroles in the proximal zone. It suggests that arsenic was mainly originated from the pyroclastic deposits of Campi Flegrei and some of the seepages with hydrothermal component, supported by low contribution of the variables in robust PCA of the sediments from distal zone. Therefore, this pioneering article suggests CoDA as a powerful tool for answering the long-lasting questions over sediment geochemistry in polluted areas.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Bahías , Análisis de Datos , Monitoreo del Ambiente , Sedimentos Geológicos , Italia , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis
12.
ACS Chem Neurosci ; 12(8): 1449-1462, 2021 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-33844495

RESUMEN

Alzheimer's disease (AD) is a progressive neurodegenerative condition affecting people in the elderly. Targeting aggregation of ß-amyloid peptides (Aß) is considered a promising approach for the therapeutic treatment of the disease. Peptide based inhibitors of ß-amyloid fibrillation are emerging as safe drug candidates as well as interesting compounds for early diagnosis of AD. Peptide conjugation via covalent bond with functional moieties enables the resultant hybrid system to acquire desired functions. Here we report the synthesis, the structural characterization, and the Aß42 interaction of a p-amino-calix[4]arene derivative bearing a GPGKLVFF peptide pendant at the lower rim. We demonstrate that the p-amino-calix[4]arene-GPGKLVFF conjugate alters the Aß42 aggregation pathways by preventing Aß42's conformational transition from random coil to ß-sheet with concomitant changes of the aggregation kinetic profile as evidenced by circular dichroism (CD), thioflavin T (ThT), and dynamic light scattering (DLS) measurements, respectively. High resolution mass spectrometry (HR-MS) confirmed a direct interaction of the p-amino-calix[4]arene-GPGKLVFF conjugate with Aß42 monomer which provided insight into a possible working mechanism, whereas the alteration of the Aß42's fibrillary architecture, by the calix-peptide conjugate, was further validated by atomic force microscopy (AFM) imaging. Finally, the herein proposed compound was shown to be effective against Aß42 oligomers' toxicity in differentiated neuroblastoma cells, SH-SY5Y.


Asunto(s)
Enfermedad de Alzheimer , Fragmentos de Péptidos , Anciano , Péptidos beta-Amiloides , Calixarenos , Humanos , Neuronas , Fenoles
13.
Chem Phys Lipids ; 237: 105085, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33895131

RESUMEN

Currently, Alzheimer's Disease (AD) is a complex neurodegenerative condition, with limited therapeutic options. Several factors, like Amyloid ß (Aß) aggregation, tau protein hyperphosphorylation, bio-metals dyshomeostasis and oxidative stress contribute to AD pathogenesis. These pathogenic processes might occur in the aqueous phase but also on neuronal membranes. Thus, investigating the connection between Aß and biomembranes, becomes important for unveiling the molecular mechanism underlying Aß amyloidosis as a critical event in AD pathology. In this work, the interaction of two peptides, made up with hybrid sequences from Tau protein 9-16 (EVMEDHAG) or 26-33 (QGGYTMHQ) N-terminal domain and Aß16-20 (KLVFF) hydrophobic region, with full length Aß40 or Aß42 peptides is reported. The studied "chimera" peptides Ac-EVMEDHAGKLVFF-NH2 (τ9-16-KL) and Ac-QGGYTMHQKLVFF-NH2 (τ26-33-KL) are endowed with Aß recognition and metal ion interaction capabilities provided by the tau or Aß sequences, respectively. These peptides were characterized in previous study along with their metal dependent interaction and amyloidogenesis, either in the presence or absence of metal ion and artificial membranes made up with Total Lipid Brain Extract (TLBE) components, (Sciacca et al., 2020). In the present paper, the ability of the two peptides to inhibit Aß aggregation is studied using composite experimental conditions including aqueous solution, the presence of metal ions (Cu or Zn), the presence of lipid vesicles mimicking neuronal membranes as well as the co-presence of metals and TLBE artificial membranes. We used Thioflavine-T (ThT) fluorescence or MALDI-TOF spectrometry analysis of Aß limited proteolysis to respectively monitor the Aß aggregation kinetic or validation of the Aß interacting regions. We demonstrate that τ9-16-KL and τ26-33-KL peptides differently affect Aß aggregation kinetics, with the tau sequence playing a crucial role. The results are discussed in terms of chimera's peptides hydrophobicity and electrostatic driven interactions at the aqueous/membrane interface.


Asunto(s)
Péptidos beta-Amiloides/química , Cobre/química , Fragmentos de Péptidos/química , Péptidos/química , Agregado de Proteínas/fisiología , Liposomas Unilamelares/química , Zinc/química , Proteínas tau/química , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Humanos , Cinética , Péptidos/metabolismo , Espectrometría de Fluorescencia , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
14.
J Inorg Biochem ; 217: 111358, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33588277

RESUMEN

The copper(II) complexes of a peptide fragment of the R3 domain of tau protein (tau(326-333) Ac-GNIHHKPG-NH2) and its mutants (Ac-GNGHHKPG-NH2, Ac-GNIHHKAG-NH2, Ac-GNGAHKPG-NH2 and Ac-GNGHAKPG-NH2) have been studied by potentiometric and spectroscopic (UV-Vis, CD) methods. ESR spectroscopy and mass spectrometry were also used to prove the coordination mode of the mononuclear complexes and the formation of dinuclear species, respectively. It has been demonstrated that the (326-333) fragment of tau protein is a versatile and effective ligand for copper(II) coordination. The versatility of copper(II) binding is related to the presence of two adjacent histidyl residues in the sequence, which results in the coexistence of mononuclear, bis(ligand) and dinuclear complexes at different metal to ligand ratios. The 1:1 mononuclear complexes are, however, the dominant species with all peptides and the imidazole-N and one to three deprotonated amide nitrogen atoms towards the N-terminal side of the histidyl residue have been suggested as metal binding sites. This binding mode allows the formation of coordination isomers because any of the two histidine moieties can be the primary anchoring site. It is evident from the CD spectroscopic measurements that the isomers are present in almost equal concentration. The copper(II) binding affinity of the native fragment of tau protein is comparable to that of a similar 2-histidine fragment of amyloid-ß mutant, Ac-SGAEGHHQK-NH2 but the comparison with an independent histidyl residue (H32) from the N-terminal region of the protein reveals the predominance of H32 over the histidines in the R3 domain.


Asunto(s)
Complejos de Coordinación/química , Cobre/metabolismo , Fragmentos de Péptidos/metabolismo , Proteínas tau/metabolismo , Sitios de Unión , Dicroismo Circular , Cobre/química , Técnicas Electroquímicas , Espectroscopía de Resonancia por Spin del Electrón , Fragmentos de Péptidos/química , Unión Proteica , Dominios Proteicos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Proteínas tau/química
15.
Antioxidants (Basel) ; 10(2)2021 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-33572861

RESUMEN

The effect of steam and sous-vide oven procedures on liposoluble antioxidants of colored cauliflower (orange and purple) was assessed for the first time and compared with domestic practice (boiling). In raw samples, the total carotenoid content was 10-fold higher in Cheddar than in Depurple (20.9 ± 2.1 vs. 2.3 ± 0.5 mg/kg dry weight), whereas the level of tocopherols was similar (28.5 ± 4.4 vs. 33 ± 5.2 mg/kg dry weight). The Cheddar liposoluble antioxidant matter contained violaxanthin, neoxanthin, α-carotene and δ-tocopherol, not detected in Depurple. All tests increased the bioactive compounds extractability with steam oven and sous-vide displaying similar effects, lower than boiling. In boiled Cheddar cauliflower, the total carotenoids and tocopherols contents increased with cooking time until they were 13-fold and 6-fold more than in raw cauliflower, respectively. Conversely, in the Depurple variety, contents increased by half with respect to the orange variety. However, from a nutritional point of view, no differences were revealed among the three different cooking treatments in terms of vitamin A and E levels expressed in µg/100 g of fresh vegetable because of the higher water content of boiled samples that must be considered when evaluating the effect of thermal treatment on cauliflower nutritional traits.

16.
J Thorac Dis ; 13(11): 6283-6293, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34992808

RESUMEN

BACKGROUND: This observational study evaluates retrospectively the long-term outcomes after pleurectomy/decortication for pleural mesothelioma, with and without the resection/reconstruction of diaphragm and pericardium. METHODS: Data from 155 consecutive patients undergoing lung-sparing surgery for epithelial pleural mesothelioma were reviewed. Selection criteria for surgery were cT1-3, cN0-1, good performance status, age <80 years. Perioperative Pemetrexed-Platinum regimen was administered as induction in 101 cases (65.2%) and as adjuvant treatment in 54 cases (34.8%). Extended pleurectomy/decortication was performed in 87 cases (56.12%). In 68 patients (43.87%) standard pleurectomy/decortication was performed without resection/reconstruction of diaphragm and pericardium, when tumour infiltration was deemed absent after intraoperative frozen section. The log-rank test and Cox regression model were used to assess the factors affecting overall survival and recurrence free survival. RESULTS: Median follow-up was 20 months. The 2- and 5-year survival rate was 60.9% and 29.2% with a median survival of 34 months. An improved survival was observed when standard pleurectomy/decortication was carried out (P=0.007). A significant impact on survival was found comparing the TNM-stages (P=0.001), pT (P=0.002) and pN variables (P=0.001). Multivariate analysis identified the pN-status (P=0.003) and standard pleurectomy/decortication (P=0.017) as predictive for longer survival. The recurrence-free survival >12 months was strongly related to the overall survival (P<0.001). The macroscopic complete resection (P=0.001), TNM-stage (P=0.003) and pT-status (P=0.001) are related to relapse. CONCLUSIONS: Within multimodal management of pleural mesothelioma, lung-sparing surgery is a valid option even with more conservative technique. A benefit for a longer survival was observed in the early stage of disease, with pN0 and when pleurectomy/decortication is carried out, preserving diaphragm and pericardium. Recurrence is not affected by the type of surgery, and a recurrence-free interval >12 months is predictive of an increased survival when the macroscopic complete resection is achieved.

17.
Heart Lung ; 50(1): 226-230, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32703619

RESUMEN

BACKGROUND: Chest drainage systems are affected by intra and inter-observer variability and poor sensibility in detecting minimal or apparent air leaks. OBJECTIVES: Overcome intra and inter-observer variability in detecting air leaks. METHODS: After surgery, a single apical chest tube was connected to the Drentech™ PalmEVO device and air leaks were checked twice a day by observation of both bubbles-in-the-chamber and digital data. RESULTS: On a total of 624 observations, disagreement between digital and traditional systems was recorded in 60(9.6%) cases. In 25(21.4%) patients, a disagreement was recorded. Overall, the digital evaluation influenced clinical management in 13(52%). In 10(40%) patients with temporary discordant features, the presence of high pleural fluid output led to a progressive final concordance. CONCLUSIONS: Disagreement between traditional and digital systems in checking air leaks is not negligible. Digital systems could give advantages in making an objective assessment of air leaks, standardizing the timing of chest tube removal.


Asunto(s)
Neumonectomía , Neumotórax , Tubos Torácicos , Humanos , Variaciones Dependientes del Observador , Neumotórax/diagnóstico , Neumotórax/etiología
18.
Artículo en Inglés | MEDLINE | ID: mdl-33255181

RESUMEN

The coronavirus (COVID-19) pandemic was particularly invasive in Italy during the period between March and late April 2020, then decreased in both the number of infections and in the seriousness of the illness throughout the summer of 2020. In this work, we measure the severity of the disease by the ratio of Intensive Care Units (ICU) spaces occupied by COVID-19 patients and the number of Active Cases (AC) each month from April to October 2020. We also use the ratio of the number of Deaths (D) to the number of Active Cases. What clearly emerges, from rigorous statistical analysis, is a progressive decrease in both ratios until August, indicating progressive mitigation of the disease. This is particularly evident when comparing March-April with July-August; during the summer period the two ratios became roughly 18 times lower. We test such sharp decreases against possible bias in counting active cases and we confirm their statistical significance. We then interpret such evidence in terms of the well-known seasonality of the human immune system and the virus-inactivating effect of stronger UV rays in the summer. Both ratios, however, increased again in October, as ICU/AC began to increase in September 2020. These ratios and the exponential growth of infections in October indicate that the virus-if not contained by strict measures-will lead to unsustainable challenges for the Italian health system in the winter of 2020-2021.


Asunto(s)
COVID-19/epidemiología , Pandemias , Estaciones del Año , COVID-19/mortalidad , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Italia/epidemiología
19.
Int J Mol Sci ; 21(20)2020 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-33066163

RESUMEN

We investigate the interaction of hemin with four fragments of prion protein (PrP) containing from one to four histidines (PrP106-114, PrP95-114, PrP84-114, PrP76-114) for its potential relevance to prion diseases and possibly traumatic brain injury. The binding properties of hemin-PrP complexes have been evaluated by UV-visible spectrophotometric titration. PrP peptides form a 1:1 adduct with hemin with affinity that increases with the number of histidines and length of the peptide; the following log K1 binding constants have been calculated: 6.48 for PrP76-114, 6.1 for PrP84-114, 4.80 for PrP95-114, whereas for PrP106-114, the interaction is too weak to allow a reliable binding constant calculation. These constants are similar to that of amyloid-ß (Aß) for hemin, and similarly to hemin-Aß, PrP peptides tend to form a six-coordinated low-spin complex. However, the concomitant aggregation of PrP induced by hemin prevents calculation of the K2 binding constant. The turbidimetry analysis of [hemin-PrP76-114] shows that, once aggregated, this complex is scarcely soluble and undergoes precipitation. Finally, a detailed study of the peroxidase-like activity of [hemin-(PrP)] shows a moderate increase of the reactivity with respect to free hemin, but considering the activity over long time, as for neurodegenerative pathologies, it might contribute to neuronal oxidative stress.


Asunto(s)
Hemina/química , Fragmentos de Péptidos/química , Proteínas Priónicas/química , Sitios de Unión , Oxidación-Reducción , Fragmentos de Péptidos/metabolismo , Polimerizacion , Unión Proteica
20.
Sci Rep ; 10(1): 11495, 2020 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-32661344

RESUMEN

Large earthquakes occurring worldwide have long been recognized to be non Poisson distributed, so involving some large scale correlation mechanism, which could be internal or external to the Earth. Till now, no statistically significant correlation of the global seismicity with one of the possible mechanisms has been demonstrated yet. In this paper, we analyze 20 years of proton density and velocity data, as recorded by the SOHO satellite, and the worldwide seismicity in the corresponding period, as reported by the ISC-GEM catalogue. We found clear correlation between proton density and the occurrence of large earthquakes (M > 5.6), with a time shift of one day. The significance of such correlation is very high, with probability to be wrong lower than 10-5. The correlation increases with the magnitude threshold of the seismic catalogue. A tentative model explaining such a correlation is also proposed, in terms of the reverse piezoelectric effect induced by the applied electric field related to the proton density. This result opens new perspectives in seismological interpretations, as well as in earthquake forecast.

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