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The programmed ribosomal frameshift (PRF) region is found in the RNA genome of all coronaviruses and shifts the ribosome reading frame through formation of a three-stem pseudoknot structure, allowing the translation of essential viral proteins. Using NMR spectroscopy, comparative sequence analyses and functional assays we show that, in the absence of the ribosome, a 123-nucleotide sequence encompassing the PRF element of SARS-CoV-2 adopts a well-defined two-stem loop structure that is conserved in all SARS-like coronaviruses. In this conformation, the attenuator hairpin and slippery site nucleotides are exposed in the first stem-loop and two pseudoknot stems are present in the second stem-loop, separated by an 8-nucleotide bulge. Formation of the third pseudoknot stem depends on pairing between bulge nucleotides and base-paired nucleotides of the upstream stem-loop, as shown by a PRF construct where residues of the upstream stem were removed, which formed the pseudoknot structure and had increased frameshifting activity in a dual-luciferase assay. The base-pair switch driving PRF pseudoknot folding was found to be conserved in several human non-SARS coronaviruses. The collective results suggest that the frameshifting pseudoknot structure of these viruses only forms transiently in the presence of the translating ribosome. These findings clarify the frameshifting mechanism in coronaviruses and can have a beneficial impact on antiviral drug discovery.
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In a family with inappropriate sinus tachycardia (IST), we identified a mutation (p.V240M) of the hyperpolarization-activated cyclic nucleotide-gated type 4 (HCN4) channel, which contributes to the pacemaker current (If) in human sinoatrial node cells. Here, we clinically study fifteen family members and functionally analyze the p.V240M variant. Macroscopic (IHCN4) and single-channel currents were recorded using patch-clamp in cells expressing human native (WT) and/or p.V240M HCN4 channels. All p.V240M mutation carriers exhibited IST that was accompanied by cardiomyopathy in adults. IHCN4 generated by p.V240M channels either alone or in combination with WT was significantly greater than that generated by WT channels alone. The variant, which lies in the N-terminal HCN domain, increased the single-channel conductance and opening frequency and probability of HCN4 channels. Conversely, it did not modify the channel sensitivity for cAMP and ivabradine or the level of expression at the membrane. Treatment with ivabradine based on functional data reversed the IST and the cardiomyopathy of the carriers. In computer simulations, the p.V240M gain-of-function variant increases If and beating rate and thus explains the IST of the carriers. The results demonstrate the importance of the unique HCN domain in HCN4, which stabilizes the channels in the closed state.
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Cardiomiopatías , Canales Regulados por Nucleótidos Cíclicos Activados por Hiperpolarización , Adulto , Humanos , Canales Regulados por Nucleótidos Cíclicos Activados por Hiperpolarización/genética , Taquicardia Sinusal , Canales de Potasio/genética , Ivabradina/farmacología , Canales Catiónicos Regulados por Nucleótidos Cíclicos/genética , Canales Catiónicos Regulados por Nucleótidos Cíclicos/metabolismo , Mutación con Ganancia de Función , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Nodo Sinoatrial , Cardiomiopatías/genéticaRESUMEN
BACKGROUND AND AIMS: Transcatheter pulmonary valve implantation (TPVI) is indicated to treat right-ventricular outflow tract (RVOT) dysfunction related to congenital heart disease (CHD). Outcomes of TPVI with the SAPIEN 3 valve that are insufficiently documented were investigated in the EUROPULMS3 registry of SAPIEN 3-TPVI. METHODS: Patient-related, procedural, and follow-up outcome data were retrospectively assessed in this observational cohort from 35 centres in 15 countries. RESULTS: Data for 840 consecutive patients treated in 2014-2021 at a median age of 29.2 (19.0-41.6) years were obtained. The most common diagnosis was conotruncal defect (70.5%), with a native or patched RVOT in 50.7% of all patients. Valve sizes were 20, 23, 26, and 29â mm in 0.4%, 25.5%, 32.1%, and 42.0% of patients, respectively. Valve implantation was successful in 98.5% [95% confidence interval (CI), 97.4%-99.2%] of patients. Median follow-up was 20.3 (7.1-38.4) months. Eight patients experienced infective endocarditis; 11 required pulmonary valve replacement, with a lower incidence for larger valves (P = .009), and four experienced pulmonary valve thrombosis, including one who died and three who recovered with anticoagulation. Cumulative incidences (95%CI) 1, 3, and 6 years after TPVI were as follows: infective endocarditis, 0.5% (0.0%-1.0%), 0.9% (0.2%-1.6%), and 3.8% (0.0%-8.4%); pulmonary valve replacement, 0.4% (0.0%-0.8%), 1.3% (0.2%-2.4%), and 8.0% (1.2%-14.8%); and pulmonary valve thrombosis, 0.4% (0.0%-0.9%), 0.7% (0.0%-1.3%), and 0.7% (0.0%-1.3%), respectively. CONCLUSIONS: Outcomes of SAPIEN 3 TPVI were favourable in patients with CHD, half of whom had native or patched RVOTs.
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Endocarditis Bacteriana , Endocarditis , Cardiopatías Congénitas , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Insuficiencia de la Válvula Pulmonar , Válvula Pulmonar , Trombosis , Adulto , Humanos , Cateterismo Cardíaco/efectos adversos , Endocarditis/epidemiología , Endocarditis Bacteriana/complicaciones , Cardiopatías Congénitas/complicaciones , Prótesis Valvulares Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Diseño de Prótesis , Válvula Pulmonar/cirugía , Insuficiencia de la Válvula Pulmonar/epidemiología , Insuficiencia de la Válvula Pulmonar/cirugía , Sistema de Registros , Estudios Retrospectivos , Trombosis/etiología , Resultado del TratamientoRESUMEN
BACKGROUND: Currently, there is a lack of effective treatments or preventive strategies for bronchopulmonary dysplasia (BPD). Pre-clinical studies with mesenchymal stromal cells (MSCs) have yielded encouraging results. The safety of administering repeated intravenous doses of umbilical cord tissue-derived mesenchymal stromal cells (UC-MSCs) has not yet been tested in extremely-low-gestational-age newborns (ELGANs). AIMS: to test the safety and feasibility of administering three sequential intravenous doses of UC-MSCs every 7 days to ELGANs at risk of developing BPD. METHODS: In this phase 1 clinical trial, we recruited ELGANs (birth weight ≤1250 g and ≤28 weeks in gestational age [GA]) who were on invasive mechanical ventilation (IMV) with FiO2 ≥ 0.3 at postnatal days 7-14. Three doses of 5 × 106/kg of UC-MSCs were intravenously administered at weekly intervals. Adverse effects and prematurity-related morbidities were recorded. RESULTS: From April 2019 to July 2020, 10 patients were recruited with a mean GA of 25.2 ± 0.8 weeks and a mean birth weight of 659.8 ± 153.8 g. All patients received three intravenous UC-MSC doses. The first dose was administered at a mean of 16.6 ± 2.9 postnatal days. All patients were diagnosed with BPD. All patients were discharged from the hospital. No deaths or any serious adverse events related to the infusion of UC-MSCs were observed during administration, hospital stays or at 2-year follow-up. CONCLUSIONS: The administration of repeated intravenous infusion of UC-MSCs in ELGANs at a high risk of developing BPD was feasible and safe in the short- and mid-term follow-up.
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Displasia Broncopulmonar , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Cordón Umbilical , Humanos , Displasia Broncopulmonar/terapia , Femenino , Trasplante de Células Madre Mesenquimatosas/métodos , Masculino , Células Madre Mesenquimatosas/citología , Recién Nacido , Cordón Umbilical/citología , Estudios de Seguimiento , Administración Intravenosa , Edad Gestacional , Recien Nacido PrematuroRESUMEN
DTG/DTS rhodopsin, which was named based on a three-residue motif (DTG or DTS) that is important for its function, is a light-driven proton-pumping microbial rhodopsin using a retinal chromophore. In contrast to other light-driven ion-pumping rhodopsins, DTG/DTS rhodopsin does not have a cytoplasmic proton donor residue, such as Asp, Glu, or Lys. Because of the lack of cytoplasmic proton donor residue, proton directly binds to the retinal chromophore from the cytoplasmic solvent. However, mutational experiments that showed the complicated effects of mutations were not able to clarify the roles played by each residue, and the detail of proton uptake pathway is unclear because of the lack of structural information. To understand the proton transport mechanism of DTG/DTS rhodopsin, here we report the three-dimensional structure of one of the DTG/DTS rhodopsins, PspR from Pseudomonas putida, by X-ray crystallography. We show that the structure of the cytoplasmic side of the protein is significantly different from that of bacteriorhodopsin, the best-characterized proton-pumping rhodopsin, and large cytoplasmic cavities were observed. We propose that these hydrophilic cytoplasmic cavities enable direct proton uptake from the cytoplasmic solvent without the need for a specialized cytoplasmic donor residue. The introduction of carboxylic residues homologous to the cytoplasmic donors in other proton-pumping rhodopsins resulted in higher pumping activity with less pH dependence, suggesting that DTG/DTS rhodopsins are advantageous for producing energy and avoiding intracellular alkalization in soil and plant-associated bacteria.
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Bombas de Protones , Rodopsina , Cristalografía por Rayos X , Luz , Bombas de Protones/química , Protones , Rodopsina/metabolismo , Rodopsinas Microbianas/química , SolventesRESUMEN
Microbial rhodopsins are a large family of photoreceptive membrane proteins with diverse light-regulated functions. While the most ubiquitous microbial rhodopsins are light-driven outward proton (H+) pumps, new subfamilies of microbial rhodopsins transporting H+ inwardly, i.e., light-driven inward H+ pumps, have been discovered recently. Although structural and spectroscopic studies provide insights into their ion transport mechanisms, the minimum key element(s) that determine the direction of H+ transport have not yet been clarified. Here, we conducted the first functional conversion study by substituting key amino acids in a natural outward H+-pumping rhodopsin (PspR) with those in inward H+-pumping rhodopsins. Consequently, an artificial inward H+ pump was constructed by mutating only three residues of PspR. This result indicates that these residues govern the key processes that discriminate between outward and inward H+ pumps. Spectroscopic studies revealed the presence of an inward H+-accepting residue in the H+ transport pathway and direct H+ uptake from the extracellular solvent. This finding of the simple element for determining H+ transport would provide a new basis for understanding the concept of ion transport not only by microbial rhodopsins but also by other ion-pumping proteins.
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Bombas de Protones , Rodopsina , Bombas de Protones/química , Rodopsina/química , Rodopsinas Microbianas/metabolismo , Transporte Iónico , Bombas Iónicas/metabolismo , Protones , LuzRESUMEN
Strain HF14-78462T is an environmental bacterium found in clinical samples from an immunocompromized patient in 2014 at Hospital Universitari i Politècnic La Fe (Valencia, Spain). Phenotypically, strain HF14-78462T cells were Gram-stain-negative, aerobic, non-spore forming and non-motile small rods which formed mucous and whitish-translucent colonies when incubated at 20-36 °C. Phylogenetic analyses based on the 16S rRNA genes and the whole genomes of closest sequenced relatives confirmed that strain HF14-78462T is affiliated with the genus Starkeya. The strain was oxidase, catalase and urease positive; but indole, lysine decarboxylase, ornithine decarboxylase and DNase negative, did not produce H2S and was able to utilize a wide variety of carbon sources including acetamide, adonitol, amygdalin, l-arabinose, citric acid, glucose, mannitol and melibiose. Unlike Starkeya novella and Starkeya koreensis, strain HF14-78462T failed to grow in thiosulphate-oxidizing media and had a narrower temperature growth range. Its genome was characterized by a size of 4.83 Mbp and a C+G content of 67.75âmol%. Major fatty acids were C18:1 ω7c, cyclo C19â:â0 and C16â:â0, its polar acids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an aminophospholipid; while the ubiquinones were Q9 (1.8â%) and Q10 (98.2â%). Digital DNA-DNA hybridization values were 41 and 41.4 against S. novella and S. koreensis, respectively, while average nucleotide identity values were around 84â%. Phenotypic, average nucleotide identity and phylogenomic comparative studies suggest that strain HF14-78462T is a new representative of the genus Starkeya and the name Starkeya nomas sp. nov. is proposed. The type strain is HF14-78462T (=CECT 30124T=LMG 31874T).
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Ácidos Grasos , Noma , Humanos , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Composición de Base , BacteriasRESUMEN
AIM: To characterize the subgingival microbiome in subjects with different periodontal health statuses. MATERIALS AND METHODS: In this cross-sectional observational study, subgingival samples were harvested from Spanish subjects with different periodontal health statuses, based on the 2018 Classification of Periodontal and Peri-Implant Diseases and Conditions. Samples were processed using high-throughput sequencing technologies (Illumina MiSeq). Taxa differentially abundant were identified using Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC). α- and ß-diversity metrics were calculated using q2-diversity in QIIME2. The analyses were adjusted for age, gender and smoking status. RESULTS: The identified subgingival microbiome showed statistically significant differences among subjects, categorized into periodontal health, gingivitis and stages I-II and III-IV periodontitis (p < .05). In patients with severe (stages III-IV) periodontitis, the genera Filifactor and Fretibacterium were detected 24 times more frequently than in periodontally healthy subjects. Similarly, the genera Porphyromonas, Prevotella and Tannerella were detected four times more frequently (p < .05). The genera Granulicatella, Streptococcus, Paracoccus, Pseudomonas, Haemophilus, Actinobacteria, Bergeyella and Capnocytophaga were significantly associated with healthier periodontal status (p < .05). CONCLUSIONS: Significant differences were detected in the subgingival microbiome among periodontal health, gingivitis and stages I-II or III-IV periodontitis, suggesting overlapping, yet distinguishable microbial profiles.
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Gingivitis , Microbiota , Periodontitis , Humanos , Estudios Transversales , Periodontitis/microbiología , Gingivitis/microbiología , Bacterias , ARN Ribosómico 16SRESUMEN
AIM: To explore the potential mechanisms of neuroinflammation (microglia, blood-brain barrier [BBB] permeability, and the sphingosine-1-phosphate [S1P] pathways) resulting from the association between periodontitis and depression in rats. MATERIALS AND METHODS: This pre-clinical in vivo experimental study used Wistar rats, in which experimental periodontitis (P) was induced by using oral gavages with Porphyromonas gingivalis and Fusobacterium nucleatum. Then, a chronic mild stress (CMS) model was implemented to induce a depressive-like behaviour, resulting in four groups: P with CMS (P+CMS+), P without CMS (P+CMS-), CMS without P (P-CMS+), and control (P-CMS-). After harvesting brain samples, protein/mRNA expression analyses and fluorescence immunohistochemistry were performed in the frontal cortex (FC). Results were analysed by ANOVA. RESULTS: CMS exposure increased the number of microglia (an indicator of neuroinflammation) in the FC. In the combined model (P+CMS+), there was a decrease in the expression of tight junction proteins (zonula occludens-1 [ZO-1], occludin) and an increase in intercellular and vascular cell adhesion molecules (ICAM-1, VCAM-1) and matrix metalloproteinase 9 (MMP9), suggesting a more severe disruption of the BBB. The enzymes and receptors of S1P were also differentially regulated. CONCLUSIONS: Microglia, BBB permeability, and S1P pathways could be relevant mechanisms explaining the association between periodontitis and depression.
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Barrera Hematoencefálica , Periodontitis , Ratas , Animales , Barrera Hematoencefálica/metabolismo , Ratas Wistar , Enfermedades Neuroinflamatorias , Depresión , Periodontitis/metabolismoRESUMEN
Preservation of blood vessel integrity, which is critical for normal physiology and organ function, is controlled at multiple levels, including endothelial junctions. However, the mechanism that controls the adequate assembly of endothelial cell junctions is not fully defined. Here, we uncover TAp73 transcription factor as a vascular architect that orchestrates transcriptional programs involved in cell junction establishment and developmental blood vessel morphogenesis and identify Angiomotin (AMOT) as a TAp73 direct transcriptional target. Knockdown of p73 in endothelial cells not only results in decreased Angiomotin expression and localization at intercellular junctions, but also affects its downstream function regarding Yes-associated protein (YAP) cytoplasmic sequestration upon cell-cell contact. Analysis of adherens junctional morphology after p73-knockdown in human endothelial cells revealed striking alterations, particularly a sharp increase in serrated junctions and actin bundles appearing as stress fibers, both features associated with enhanced barrier permeability. In turn, stabilization of Angiomotin levels rescued those junctional defects, confirming that TAp73 controls endothelial junction dynamics, at least in part, through the regulation of Angiomotin. The observed defects in monolayer integrity were linked to hyperpermeability and reduced transendothelial electric resistance. Moreover, p73-knockout retinas showed a defective sprout morphology coupled with hemorrhages, highlighting the physiological relevance of p73 regulation in the maintenance of vessel integrity in vivo. We propose a new model in which TAp73 acts as a vascular architect integrating transcriptional programs that will impinge with Angiomotin/YAP signaling to maintain junctional dynamics and integrity, while balancing endothelial cell rearrangements in angiogenic vessels.
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Angiomotinas , Células Endoteliales , Actinas/metabolismo , Cadherinas/metabolismo , Células Endoteliales/metabolismo , Humanos , Uniones Intercelulares/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas Señalizadoras YAPRESUMEN
Cantabria Cohort stems from a research and action initiative lead by researchers from Valdecilla Research Institute (IDIVAL), Marqués de Valdecilla University Hospital and University of Cantabria, supported by the regional Goverment. Its aim is to identify and follow up a cohort that would provide information to improve the understanding of the etiology and prognosis of different acute and chronic diseases. The Cantabria Cohort will recruit between 40,000-50,000 residents aged 40-69 years at baseline, representing 10-20% of the target population. Currently, more than 30,000 volunteers have been enrolled. All participants will be invited for a re-assessment every three years, while the overall duration is planned for twenty years. The repeated collection of biomaterials combined with broad information from participant questionnaires, medical examinations, actual health system records and other secondary public data sources is a major strength of its design, which will make it possible to address biological pathways of disease development, identify new factors involved in health and disease, design new strategies for disease prevention, and advance precision medicine. It is conceived to allow access to a large number of researchers worldwide to boost collaboration and medical research.
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Atención a la Salud , Humanos , España/epidemiología , Pronóstico , Enfermedad Crónica , CausalidadRESUMEN
PURPOSE: Differentiating subtalar and ankle instability in the clinical setting is challenging. This study aims to analyze the rotational laxity of the subtalar joint bilaterally in patients with asymptomatic and symptomatic ankle instability under simulated load and stress-induced position of the subtalar joint. METHODS: A case-control study was conducted using an adjustable load device (ALD). Patients with chronic ankle instability and healthy volunteers were included. Each subject underwent a CT scan under mechanical stress and simulated weight-bearing conditions, maintaining maximum eversion and inversion hindfoot positions. The images were obtained in a single model, allowing calculations of the motion vector as well as the helical axis. The helical axis was defined by a rotation angle and a translation distance. RESULTS: A total of 72 feet were included in the study. Thirty-one patients with unilateral symptoms and five healthy controls were selected, defining two groups: symptomatic (n = 31) and asymptomatic (n = 41). An absolute difference of 4.6º (95%CI 2-11.1) rotation angle was found on the helical axis of the symptomatic vs. asymptomatic group (p = 0.001). No significant differences were detected in the translation distance (n.s.) between the groups. Additionally, a significant positive correlation was found between the rotation angle and translation distance through the helical axis in the asymptomatic group (r = 0.397, p = 0.027). CONCLUSION: Patients with chronic ankle instability suspected of having subtalar joint instability showed a wider subtalar range of laxity in terms of rotation about the helical axis. Furthermore, differences in kinematics between symptomatic and asymptomatic hindfeet was demonstrated when both feet were compared. LEVEL OF EVIDENCE: III.
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The irradiation of 2-aryl-4-(E-3'-aryl-allylidene)-5(4H)-oxazolones 1 with blue light (456 nm) in the presence of [Ru(bpy)3](BF4)2 (bpy = 2,2'-bipyridine, 5% mol) gives the unstable cyclobutane-bis(oxazolones) 2 by [2+2]-photocycloaddition of two oxazolones 1. Each oxazolone contributes to the formation of 2 with a different C=C bond, one of them reacting through the exocyclic C=C bond, while the other does so through the styryl group. Treatment of unstable cyclobutanes 2 with NaOMe/MeOH produces the oxazolone ring opening reaction, affording stable styryl-cyclobutane bis(amino acids) 3. The reaction starts with formation of the T1 excited state of the photosensitizer 3[Ru*(bpy)3]2+, which reacts with S0 of oxazolones 1 through energy transfer to give the oxazolone T1 state 3(oxa*)-1, which is the reactive species and was characterized by transient absorption spectroscopy. Measurement of the half-life of 3(oxa*)-1 for 1a, 1b and 1d shows large values for 1a and 1b (10-12 µs), while that of 1d is shorter (726 ns). Density functional theory (DFT) modeling displays strong structural differences in the T1 states of the three oxazolones. Moreover, study of the spin density of T1 state 3(oxa*)-1 provides clues to understanding the different reactivity of 4-allylidene-oxazolones described here with respect to the previously reported 4-arylidene-oxazolones.
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Ciclobutanos , Oxazolona , Aminoácidos , Reacción de Cicloadición , Fármacos FotosensibilizantesRESUMEN
Plastic production, disposal, and recycling systems represent one of the higher challenges for the planet's health. Its direct consequence is the release of endocrine disruptors, such as bisphenol A (BPA), and its emerging substitute molecules, bisphenol F and S (BPF and BPS), into the environment. Consequently, bisphenols are usually present in human biological fluids. Since BPA, BPS, and BPF have structural analogies and similar hormonal activity, their combined study is urgently needed. The present manuscript studied the effect of the mixture of bisphenols (BPmix) in one of the world's largest human cohorts (NHANES cohort). Descriptive and comparative statistics, binomial and multinomial logistic regression, weighted quantile sum regression, quantile g-computation, and Bayesian kernel machine regression analysis determined a positive association between BPmix and heart disease, including confounders age, gender, BMI, ethnicity, Poverty/Income Ratio, and serum cotinine. Endothelial dysfunction is a hallmark of cardiovascular disease; thus, the average ratio of bisphenols found in humans was used to conduct murine aortic endothelial cell studies. The first results showed that BPmix had a higher effect on cell viability than BPA, enhancing its deleterious biological action. However, the flow cytometry, Western blot, and immunofluorescence assays demonstrated that BPmix induces a differential effect on cell death. While BPA exposure induces necroptosis, its combination with the proportion determined in the NHANES cohort induces apoptosis. In conclusion, the evidence suggests the need to reassess research methodologies to study endocrine disruptors more realistically.
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Disruptores Endocrinos , Cardiopatías , Humanos , Animales , Ratones , Disruptores Endocrinos/toxicidad , Endotelio Vascular/metabolismo , Teorema de Bayes , Encuestas Nutricionales , Compuestos de Bencidrilo/farmacologíaRESUMEN
The surface chemistry of nanoparticles is a key step on the pathway from particle design towards applications in biologically relevant environments. Here, a bilayer-based strategy for the surface modification of hydrophobic nanoparticles is introduced that leads to excellent colloidal stability in aqueous environments and good protection against disintegration, while permitting surface functionalization via simple carbodiimide chemistry. We have demonstrated the excellent potential of this strategy using upconversion nanoparticles (UCNPs), initially coated with oleate and therefore dispersible only in organic solvents. The hydrophobic oleate capping is maintained and a bilayer is formed upon addition of excess oleate. The bilayer approach renders protection towards luminescence loss by water quenching, while the incorporation of additional molecules containing amino functions yields colloidal stability and facilitates the introduction of functionality. The biological relevance of the approach was confirmed with the use of two model dyes, a photosensitizer and a nitric oxide (NO) probe that, when attached to the surface of the UCNPs, retained their functionality to produce singlet oxygen and detect intracellular NO, respectively. We present a simple and fast strategy to protect and functionalize inorganic nanoparticles in biological media, which is important for controlled surface engineering of nanosized materials for theranostic applications.
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Nanopartículas , Ácido Oléico , Nanopartículas/química , Agua/química , Solventes/química , Oxígeno Singlete/químicaRESUMEN
The irradiation of (Z)-2-phenyl-4-aryliden-5(4H)-oxazolones 1 in deoxygenated CH2Cl2 at 25 °C with blue light (465 nm) in the presence of [Ru(bpy)3](BF4)2 (5% mole ratio) as a triplet photocatalyst promotes the [2+2] photocycloaddition of the CâC bonds of the 4-arylidene moiety, thus allowing the completely regio- and stereoselective formation of cyclobutane-bis(oxazolone)s 2 as single stereoisomers. Cyclobutanes 2 have been unambiguously characterized as the µ-isomers and contain two E-oxazolones coupled in an anti-head-to-head form. The use of continuous-flow techniques in microreactors allows the synthesis of cyclobutanes 2 in only 60 min, compared with the 24-48 h required in batch mode. Ring opening of the oxazolone heterocycle in 2 with a base affords the corresponding 1,2-diaminotruxinic bis-amino esters 3, which are also obtained selectively as µ-isomers. The ruthenium complex behaves as a triplet photocatalyst, generating the reactive excited state of the oxazolone via an energy-transfer process. This reactive excited state has been characterized as a triplet diradical 3(E/Z)-1* by laser flash photolysis (transient absorption spectroscopy). This technique also shows that this excited state is the same when starting from either (Z)- or (E)-oxazolones. Density functional theory calculations show that the first step of the [2+2] cycloaddition between 3(E/Z)-1* and (Z)-1 is formation of the C(H)-C(H) bond and that (Z) to (E) isomerization takes place at the 1,4-diradical thus formed.
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Ciclobutanos , Rutenio , Aminoácidos , Oxazolona/química , Rutenio/química , EstereoisomerismoRESUMEN
The rise of antibacterial drug resistance means treatment options are becoming increasingly limited. We must find ways to tackle these hard-to-treat drug-resistant and biofilm infections. With the lack of new antibacterial drugs (such as antibiotics) reaching the clinics, research has switched focus to exploring alternative strategies. One such strategy is antibacterial photodynamic therapy (aPDT), a system that relies on light, oxygen, and a non-toxic dye (photosensitiser) to generate cytotoxic reactive oxygen species. This technique has already been shown capable of handling both drug-resistant and biofilm infections but has limited clinical approval to date, which is in part due to the low bioavailability and selectivity of hydrophobic photosensitisers. Nanotechnology-based techniques have the potential to address the limitations of current aPDT, as already well-documented in anti-cancer PDT. Here, we review recent advances in nanoparticle-based targeting tactics for aPDT.
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Antibacterianos , Nanopartículas , Fotoquimioterapia , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Biopelículas , Sistemas de Liberación de Medicamentos , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéuticoRESUMEN
BACKGROUND: Pain is a common symptom in patients with advanced, metastatic, or terminal cancer. Neuropathic pain and psycho-emotional suffering are factors that increase the difficulty of pain management. Pain control in patients with cancer remains a challenge for medical professionals. STUDY QUESTION: What is the evolution of neuropathic/mixed pain compared with nociceptive pain under standardized treatment in patients with cancer? STUDY DESIGN: A prospective, longitudinal, open-label, nonrandomized study was conducted on patients with cancer pain. MEASURES AND OUTCOMES: Pain type was assessed at admission using the modified Brief Pain Inventory, and pain intensity was assessed daily using the Numerical Rating Scale for 14 days and on days 21 and 28. Screening of depression was performed on days 1, 7, 14, 21, and 28 using the Hamilton Depression Rating Scale. Patients with pain and depression received analgesics with antidepressants, while patients without depression received analgesics or analgesics with an anticonvulsant depending on the pain subtype. RESULTS: Of 72 patients, 23 had nociceptive pain and 49 had neuropathic/mixed pain. At admission, pain intensity was higher for patients with neuropathic/mixed pain compared with nociceptive pain (mean values: 7.06 vs. 5.82) with statistical significance ( P = 0.001) and remained as such at the end of this study (mean values: 3.77 vs. 2.73). A decrease in the mean pain intensity was observed in all types of pain, but without statistical significance regardless of pain type and treatment protocol used ( P = 0.77). If depression was present, antidepressants combined with analgesics decreased pain and depression scores significantly ( P = 0.001). CONCLUSIONS: Patients with neuropathic/mixed pain have higher levels of pain and lower response to treatment. Identifying psycho-emotional suffering can improve pain control by intervening in the physical and psycho-emotional components of pain.
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Dolor en Cáncer , Neuralgia , Dolor Nociceptivo , Cuidados Paliativos , Analgésicos/uso terapéutico , Dolor en Cáncer/tratamiento farmacológico , Dolor en Cáncer/psicología , Depresión/diagnóstico , Depresión/tratamiento farmacológico , Humanos , Estudios Longitudinales , Neuralgia/tratamiento farmacológico , Neuralgia/psicología , Dolor Nociceptivo/tratamiento farmacológico , Dolor Nociceptivo/psicología , Cuidados Paliativos/métodos , Estudios ProspectivosRESUMEN
Viral infections affect several million patients annually. Although hundreds of viruses are known to be pathogenic, only a few can be treated in the clinic with available antiviral drugs. Naturally based pharmacotherapy may be a proper alternative for treating viral diseases. Several natural and semisynthetic abietane-type diterpenoids have shown important antiviral activities. In this study, a biological evaluation of a number of either C-18- or C-19-functionalized known semisynthetic abietanes against Zika virus, Dengue virus, Herpes virus simplex type 1, and Chikungunya virus are reported. Semisynthetic abietane ferruginol and its analogue 18-(phthalimid-2-yl)ferruginol displayed broad-spectrum antiviral properties. The scale-up synthesis of this analogue has been optimized for further studies and development. This molecule displayed an EC50 between 5.0 and 10.0 µM against Colombian Zika virus strains and EC50 = 9.8 µM against Chikungunya virus. Knowing that this ferruginol analogue is also active against Dengue virus type 2 (EC50 = 1.4 µM, DENV-2), we can conclude that this compound is a promising broad-spectrum antiviral agent paving the way for the development of novel antivirals.
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Virus Chikungunya , Virus , Infección por el Virus Zika , Virus Zika , Abietanos/farmacología , Antivirales , Humanos , Replicación Viral , Infección por el Virus Zika/tratamiento farmacológicoRESUMEN
End-of-the-century predictions on carbon dioxide (CO2) driven ocean acidification and the continuous leakage of pesticides from inland to coastal areas are of concern for potential negative effects on marine species' early life stages which are the most vulnerable to environmental changes. Variations in seawater chemistry related to human activities may interfere with the normal development from embryo to juvenile/adult stage. However, transgenerational studies suggest that the parental generation can influence the offspring phenotype, and thus their performances, based on the environment experienced. Here we compared the transgenerational responses to a multiple stressor scenario in sea urchins (Paracentrotus lividus) that experienced different environments since their settlement: i.e., animals from a highly variable environment, such as the Venice lagoon, versus animals from a coastal area with prevailing oligotrophic conditions in the Northern Adriatic Sea. After long-term maintenance (2 and 6 months) of adult sea urchins at natural and -0.4 units reduced pH, the F1 generations were obtained. Embryos were reared under four experimental conditions: natural and -0.4 pH both in the absence and in the presence of an emerging contaminants' mixture (glyphosate and aminomethylphosphonic acid at environmentally relevant concentrations, 100 µg/L). A significant detrimental effect of both the parental and the filial pH was highlighted, affecting embryo development and growth. Nonetheless, sea urchins from both sites were able to cope with ocean acidification. The 6-months F1 response was better than that of the 2-months F1. Conversely, the F1 response of the sea urchins maintained at natural conditions did not change sensibly after more prolonged parental exposure. An additive but mild negative effect of the mixture was observed, mostly in lagoon offspring. Results suggest that long-term exposure to reduced pH leads to transgenerational acclimation but does not affect susceptibility to the tested pollutants.