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Dynamins are large GTPases whose primary function is not only to catalyze membrane scission during endocytosis but also to modulate other cellular processes, such as actin polymerization and vesicle trafficking. Recently, we reported that centronuclear myopathy associated dynamin-2 mutations, p.A618T, and p.S619L, impair Ca2+-induced exocytosis of the glucose transporter GLUT4 containing vesicles in immortalized human myoblasts. As exocytosis and endocytosis occur within rapid timescales, here we applied high-temporal resolution techniques, such as patch-clamp capacitance measurements and carbon-fiber amperometry to assess the effects of these mutations on these two cellular processes, using bovine chromaffin cells as a study model. We found that the expression of any of these dynamin-2 mutants inhibits a dynamin and F-actin-dependent form of fast endocytosis triggered by single action potential stimulus, as well as inhibits a slow compensatory endocytosis induced by 500 ms square depolarization. Both dynamin-2 mutants further reduced the exocytosis induced by 500 ms depolarizations, and the frequency of release events and the recruitment of neuropeptide Y (NPY)-labeled vesicles to the cell cortex after stimulation of nicotinic acetylcholine receptors with 1,1-dimethyl-4-phenyl piperazine iodide (DMPP). They also provoked a significant decrease in the Ca2+-induced formation of new actin filaments in permeabilized chromaffin cells. In summary, our results indicate that the centronuclear myopathy (CNM)-linked p.A618T and p.S619L mutations in dynamin-2 affect exocytosis and endocytosis, being the disruption of F-actin dynamics a possible explanation for these results. These impaired cellular processes might underlie the pathogenic mechanisms associated with these mutations.
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Células Cromafins , Dinamina II , Endocitose , Exocitose , Mutação , Miopatias Congênitas Estruturais , Células Cromafins/metabolismo , Endocitose/fisiologia , Endocitose/genética , Dinamina II/genética , Dinamina II/metabolismo , Animais , Exocitose/fisiologia , Miopatias Congênitas Estruturais/genética , Miopatias Congênitas Estruturais/patologia , Miopatias Congênitas Estruturais/metabolismo , Mutação/genética , Bovinos , Humanos , Actinas/metabolismo , Actinas/genética , Células Cultivadas , Técnicas de Patch-Clamp , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologiaRESUMO
Tritrichomonas foetus is a flagellated and anaerobic parasite able to infect cattle and felines. Despite its prevalence, there is no effective standardized or legal treatment for T. foetus-infected cattle; the vaccination still has limited success in mitigating infections and reducing abortion risk; and nowadays, the diagnosis of T. foetus presents important limitations in terms of sensitivity and specificity in bovines. Here, we characterize the plasma membrane proteome of T. foetus and identify proteins that are represented in different isolates of this protozoan. Additionally, we performed a bioinformatic analysis that revealed the antigenicity potential of some of those proteins. This analysis is the first study to identify common proteins at the plasma membrane of different T. foetus isolates that could be targets for alternative diagnostic or vaccine techniques in the future.
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Proteômica , Proteínas de Protozoários , Tritrichomonas foetus , Tritrichomonas foetus/isolamento & purificação , Proteômica/métodos , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/análise , Animais , Proteoma/análise , Membrana Celular/metabolismo , Bovinos , Proteínas de Membrana/metabolismo , Doenças dos Bovinos/parasitologia , Infecções Protozoárias em Animais/parasitologia , Infecções Protozoárias em Animais/diagnóstico , Biologia Computacional/métodosRESUMO
Pannexin1 hemichannels (Panx1 HCs) are found in the membrane of most mammalian cells and communicate the intracellular and extracellular spaces, enabling the passive transfer of ions and small molecules. They are involved in physiological and pathophysiological conditions. During apoptosis, the C-terminal tail of Panx1 is proteolytically cleaved, but the permeability features of hemichannels and their role in cell death remain elusive. To address these topics, HeLa cells transfected with full-length human Panx1 (fl-hPanx1) or C-terminal truncated hPanx1 (Δ371hPanx1) were exposed to alkaline extracellular saline solution, increasing the activity of Panx1 HCs. The Δ371hPanx1 HC was permeable to DAPI and Etd+, but not to propidium iodide, whereas fl-hPanx1 HC was only permeable to DAPI. Furthermore, the cytoplasmic Ca2+ signal increased only in Δ371hPanx1 cells, which was supported by bioinformatics approaches. The influx of Ca2+ through Δ371hPanx1 HCs was necessary to promote cell death up to about 95% of cells, whereas the exposure to alkaline saline solution without Ca2+ failed to induce cell death, and the Ca2+ ionophore A23187 promoted more than 80% cell death even in fl-hPanx1 transfectants. Moreover, cell death was prevented with carbenoxolone or 10Panx1 in Δ371hPanx1 cells, whereas it was undetectable in HeLa Panx1-/- cells. Pretreatment with Ferrostatin-1 and necrostatin-1 did not prevent cell death, suggesting that ferroptosis or necroptosis was not involved. In comparison, zVAD-FMK, a pancaspase inhibitor, reduced death by ~60%, suggesting the involvement of apoptosis. Therefore, alkaline pH increases the activity of Δ371hPanx1HCs, leading to a critical intracellular free-Ca2+ overload that promotes cell death.
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Cálcio , Conexinas , Proteínas do Tecido Nervoso , Humanos , Conexinas/metabolismo , Conexinas/genética , Células HeLa , Cálcio/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Apoptose , Morte Celular , Sinalização do CálcioRESUMO
RhoA plays a crucial role in neuronal polarization, where its action restraining axon outgrowth has been thoroughly studied. We now report that RhoA has not only an inhibitory but also a stimulatory effect on axon development depending on when and where exerts its action and the downstream effectors involved. In cultured hippocampal neurons, FRET imaging revealed that RhoA activity selectively localized in growth cones of undifferentiated neurites, whereas in developing axons it displayed a biphasic pattern, being low in nascent axons and high in elongating ones. RhoA-Rho kinase (ROCK) signaling prevented axon initiation but had no effect on elongation, whereas formin inhibition reduced axon extension without significantly altering initial outgrowth. In addition, RhoA-mDia signaling promoted axon elongation by stimulating growth cone microtubule stability and assembly, as opposed to RhoA-ROCK signaling, which restrained growth cone microtubule assembly and protrusion.
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Axônios , Cones de Crescimento , Microtúbulos , Transdução de Sinais , Proteína rhoA de Ligação ao GTP , Microtúbulos/metabolismo , Animais , Proteína rhoA de Ligação ao GTP/metabolismo , Axônios/metabolismo , Cones de Crescimento/metabolismo , Quinases Associadas a rho/metabolismo , Hipocampo/metabolismo , Hipocampo/citologia , Ratos , Forminas/metabolismo , Células Cultivadas , Neurônios/metabolismoRESUMO
Thyroxine (T4) is a drug extensively utilized for the treatment of hypothyroidism. However, the oral absorption of T4 presents certain limitations. This research investigates the efficacy of CO2 nanobubbles in water as a potential oral carrier for T4 administration to C57BL/6 hypothyroid mice. Following 18 h of fasting, the formulation was administered to the mice, demonstrating that the combination of CO2 nanobubbles and T4 enhanced the drug's absorption in blood serum by approximately 40%. To comprehend this observation at a molecular level, we explored the interaction mechanism through which T4 engages with the CO2 nanobubbles, employing molecular simulations, semi-empirical quantum mechanics, and PMF calculations. Our simulations revealed a high affinity of T4 for the water-gas interface, driven by additive interactions between the hydrophobic region of T4 and the gas phase and electrostatic interactions of the polar groups of T4 with water at the water-gas interface. Concurrently, we observed that at the water-gas interface, the cluster of T4 formed in the water region disassembles, contributing to the drug's bioavailability. Furthermore, we examined how the gas within the nanobubbles aids in facilitating the drug's translocation through cell membranes. This research contributes to a deeper understanding of the role of CO2 nanobubbles in drug absorption and subsequent release into the bloodstream. The findings suggest that utilizing CO2 nanobubbles could enhance T4 bioavailability and cell permeability, leading to more efficient transport into cells. Additional research opens the possibility of employing lower concentrations of this class of drugs, thereby potentially reducing the associated side effects due to poor absorption.
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Dióxido de Carbono , Modelos Animais de Doenças , Hipotireoidismo , Tiroxina , Água , Animais , Hipotireoidismo/tratamento farmacológico , Hipotireoidismo/metabolismo , Camundongos , Dióxido de Carbono/química , Água/química , Camundongos Endogâmicos C57BL , Administração Oral , Nanopartículas/química , Portadores de Fármacos/químicaRESUMO
Living in arid environments presents unique challenges to organisms, including limited food and water, extreme temperatures, and UV exposure. Reptiles, such as the South American leaf-toed gecko (Phyllodactylus gerrhopygus), have evolved remarkable adaptations to thrive in such harsh conditions. The gut microbiome plays a critical role in host adaptation and health, yet its composition remains poorly characterized in desert reptiles. This study aimed to characterize the composition and abundance of the gut microbiome in P. gerrhopygus inhabiting the hyperarid Atacama Desert, taking into account potential sex differences. Fecal samples from adult female and male geckos were analyzed by 16S rRNA gene amplicon sequencing. No significant differences in bacterial alpha diversity were observed between the sexes. However, the phylum Bacteroidota was more abundant in females, while males had a higher Firmicutes/Bacteroidota ratio. The core microbiome was dominated by the phyla Bacteroidota, Firmicutes, and Proteobacteria in both sexes. Analysis of bacterial composition revealed 481 amplicon sequence variants (ASVs) shared by female and male geckos. In addition, 108 unique ASVs were exclusive to females, while 244 ASVs were unique to males. Although the overall bacterial composition did not differ significantly between the sexes, certain taxa exhibited higher relative abundances in each sex group. This study provides insight into the taxonomic structure of the gut microbiome in a desert-adapted reptile and highlights potential sex-specific differences. Understanding these microbial communities is critical for elucidating the mechanisms underlying host resilience in Earth's most arid environments, and for informing conservation efforts in the face of ongoing climate change.
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We previously reported that asthma prevalence was higher in the United States (US) compared to Mexico (MX) (25.8% vs. 8.4%). This investigation assessed differences in microbial dust composition in relation to demographic and housing characteristics on both sides of the US-MX Border. Forty homes were recruited in the US and MX. Home visits collected floor dust and documented occupants' demographics, asthma prevalence, housing structure, and use characteristics. US households were more likely to have inhabitants who reported asthma when compared with MX households (30% vs. 5%) and had significantly different flooring types. The percentage of households on paved roads, with flushing toilets, with piped water and with air conditioning was higher in the US, while dust load was higher in MX. Significant differences exist between countries in the microbial composition of the floor dust. Dust from Mexican homes was enriched with Alishewanella, Paracoccus, Rheinheimera genera and Intrasporangiaceae family. A predictive metagenomics analysis identified 68 significantly differentially abundant functional pathways between US and MX. This study documented multiple structural, environmental, and demographic differences between homes in the US and MX that may contribute to significantly different microbial composition of dust observed in these two countries.
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Poeira , Habitação , Poeira/análise , Arizona , Humanos , México , Asma/epidemiologia , Asma/microbiologia , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Feminino , Características da Família , Masculino , Metagenômica/métodosRESUMO
BACKGROUND AND PURPOSE: ATP is highly accumulated in secretory vesicles and secreted upon exocytosis from neurons and endocrine cells. In adrenal chromaffin granules, intraluminal ATP reaches concentrations over 100 mM. However, how these large amounts of ATP contribute to exocytosis has not been investigated. EXPERIMENTAL APPROACH: Exocytotic events in bovine and mouse adrenal chromaffin cells were measured with single cell amperometry. Cytosolic Ca2+ measurements were carried out in Fluo-4 loaded cells. Submembrane Ca2+ was examined in PC12 cells transfected with a membrane-tethered Ca2+ indicator Lck-GCaMP3. ATP release was measured using the luciferin/luciferase assay. Knockdown of P2X7 receptors was induced with short interfering RNA (siRNA). Direct Ca2+ influx through this receptor was measured using a P2X7 receptor-GCamp6 construct. KEY RESULTS: ATP induced exocytosis in chromaffin cells, whereas the ectonucleotidase apyrase reduced the release events induced by the nicotinic agonist dimethylphenylpiperazinium (DMPP), high KCl, or ionomycin. The purinergic agonist BzATP also promoted a secretory response that was dependent on extracellular Ca2+. A740003, a P2X7 receptor antagonist, abolished secretory responses of these secretagogues. Exocytosis was also diminished in chromaffin cells when P2X7 receptors were silenced using siRNAs and in cells of P2X7 receptor knockout mice. In PC12 cells, DMPP induced ATP release, triggering Ca2+ influx through P2X7 receptors. Furthermore, BzATP, DMPP, and KCl allowed the formation of submembrane Ca2+ microdomains inhibited by A740003. CONCLUSION AND IMPLICATIONS: Autocrine activation of P2X7 receptors constitutes a crucial feedback system that amplifies the secretion of catecholamines in chromaffin cells by favouring submembrane Ca2+ microdomains.
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Trifosfato de Adenosina , Catecolaminas , Células Cromafins , Exocitose , Receptores Purinérgicos P2X7 , Animais , Receptores Purinérgicos P2X7/metabolismo , Células Cromafins/metabolismo , Células Cromafins/efeitos dos fármacos , Bovinos , Trifosfato de Adenosina/metabolismo , Camundongos , Catecolaminas/metabolismo , Exocitose/efeitos dos fármacos , Células PC12 , Ratos , Cálcio/metabolismo , Comunicação Autócrina , Camundongos Endogâmicos C57BL , Células Cultivadas , MasculinoRESUMO
The development of efficient nanoscale photon absorbers, such as plasmonic or high-index dielectric nanostructures, allows the remotely controlled release of heat on the nanoscale using light. These photothermal nanomaterials have found applications in various research and technological fields, ranging from materials science to biology. However, measuring the nanoscale thermal fields remains an open challenge, hindering full comprehension and control of nanoscale photothermal phenomena. Here, we review and discuss existent thermometries suitable for single nanoparticles heated under illumination. These methods are classified in four categories according to the region where they assess temperature: (1) the average temperature within a diffraction-limited volume, (2) the average temperature at the immediate vicinity of the nanoparticle surface, (3) the temperature of the nanoparticle itself, and (4) a map of the temperature around the nanoparticle with nanoscale spatial resolution. In the latter, because it is the most challenging and informative type of method, we also envisage new combinations of technologies that could be helpful in retrieving nanoscale temperature maps. Finally, we analyze and provide examples of strategies to validate the results obtained using different thermometry methods.
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Nanopartículas , Nanoestruturas , Temperatura Alta , Nanopartículas/química , Nanoestruturas/química , TemperaturaRESUMO
This work explores the photochemical degradation of cationic species of 7-hydroxy-1-methyl-2H-pyrido[3,4-b]indole or harmol (1C) and the corresponding partially hydrogenated derivative 7-hydroxy-1-methyl-3,4-dihydro-2H-pyrido[3,4-b]indole or harmalol (2C) in aqueous solution. UV-visible absorption and fluorescence emission spectroscopy coupled with multivariate data analysis (MCR-ALS and PARAFAC), HPLC and HRESI-MS techniques were used for both quantitative and qualitative analysis. The formation of hydrogen peroxide reactive oxygen species (ROS) was quantified, and the influence of pH, oxygen partial pressure and photoexcitation source on the photochemical degradation of both compounds was assessed. The potential implications on the biosynthesis of ßCs and their biological role in living systems are discussed.
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Alcaloides , Harmalina/análogos & derivados , Harmina/análogos & derivados , Água , Indóis , Concentração de Íons de HidrogênioRESUMO
This study reports valuable information regarding the presence and concentration of a series of photoactive ß-carboline (ßCs) alkaloids (norharmane, harmane, harmine, harmol, harmaline, and harmalol) and their distribution across the floral age and organs of Passiflora caerulea. UHPLC-MS/MS data reported herein reveal that the ßCs' content ranged from 1 to 110 µg kg-1 , depending on the floral organ and age. In certain physiologically relevant organs, such as anthers, ßCs' content was one order of magnitude higher than in other organs, suggesting a special role for ßCs in this specific organ. ßCs' content also varied in a structure-dependent manner. Alkaloids bearing a hydroxyl group at position C(7) of the main ßC ring were present at concentrations one order of magnitude higher than other ßC derivatives investigated. UV-visible and fluorescence spectroscopy of the flower extracts provided complementary information regarding other biologically relevant groups of chromophores (phenolic/indolic derivatives, flavonoids/carotenes, and chlorophylls). Since flowers are constantly exposed to solar radiation, the presence of photoactive ßCs in floral organs may have several (photo)biological implications that are further discussed.
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Alcaloides , Passiflora , Espectrometria de Massas em Tandem , Carbolinas/químicaRESUMO
BACKGROUND: 3D computed tomography (CT) has been seldom used for the evaluation of hiatal hernias (HH) in surgical patients. This study aims to describe the 3D CT findings in candidates for laparoscopic or robotic antireflux surgery or HH repair and compare them with other tests. METHODS: Thirty patients with HH and/or gastroesophageal reflux disease (GERD) who were candidates for surgical treatment and underwent high-resolution CT were recruited. The variables studied were distance from the esophagogastric junction (EGJ) to the hiatus; total gastric volume and herniated gastric volume, percentage of herniated volume in relation to the total gastric volume; diameters and area of the esophageal hiatus. RESULTS: HH was diagnosed with CT in 21 (70%) patients. There was no correlation between the distance EGJ-hiatus and the herniated gastric volume. There was a statistically significant correlation between the distance from the EGJ to the hiatus and the area of the esophageal hiatus of the diaphragm. There was correlation between tomographic and endoscopic findings for the presence and size of HH. HH was diagnosed with manometry in 9 (50%) patients. There was no correlation between tomographic and manometric findings for the diagnosis of HH and between hiatal area and lower esophageal sphincter basal pressure. There was no correlation between any parameter and DeMeester score. CONCLUSIONS: The anatomy of HH and the hiatus can be well defined by 3D CT. The EGJ-hiatus distance may be equally measured by 3D CT or upper digestive endoscopy. DeMeester score did not correlate with any anatomical parameter.
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Refluxo Gastroesofágico , Hérnia Hiatal , Laparoscopia , Procedimentos Cirúrgicos Robóticos , Humanos , Hérnia Hiatal/diagnóstico por imagem , Hérnia Hiatal/cirurgia , Refluxo Gastroesofágico/diagnóstico por imagem , Refluxo Gastroesofágico/cirurgia , Junção Esofagogástrica/diagnóstico por imagem , Junção Esofagogástrica/cirurgia , Manometria , Tomografia Computadorizada por Raios XRESUMO
Human leishmaniasis is a neglected tropical disease which affects nearly 1.5 million people every year, with Mexico being an important endemic region. One of the major defense mechanisms of these parasites is based in the polyamine metabolic pathway, as it provides the necessary compounds for its survival. Among the enzymes in this route, trypanothione reductase (TryR), an oxidoreductase enzyme, is crucial for the Leishmania genus' survival against oxidative stress. Thus, it poses as an attractive drug target, yet due to the size and features of its catalytic pocket, modeling techniques such as molecular docking focusing on that region is not convenient. Herein, we present a computational study using several structure-based approaches to assess the druggability of TryR from L. mexicana, the predominant Leishmania species in Mexico, beyond its catalytic site. Using this consensus methodology, three relevant pockets were found, of which the one we call σ-site promises to be the most favorable one. These findings may help the design of new drugs of trypanothione-related diseases.
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Antiprotozoários , Leishmania , Leishmaniose , Humanos , Simulação de Acoplamento Molecular , Leishmania/metabolismo , NADH NADPH Oxirredutases/metabolismo , Leishmaniose/parasitologia , Antiprotozoários/uso terapêuticoRESUMO
BACKGROUND: Intracranial pressure (ICP) can be continuously and reliably measured using invasive monitoring through an external ventricular catheter or an intraparenchymal probe. We explore electroencephalography (EEG) to identify a reliable real-time noninvasive ICP correlate. METHODS: Using a previously described porcine model of intracranial hypertension, we examined the cross correlation between ICP time series and the slope of the EEG power spectral density as described by Ï. We calculated Ï as tan-1 (slope of power spectral density) and normalized it by π, where slope is that of the power-law fit (log frequency vs. log power) to the power spectral density of the EEG signal. Additionally, we explored the relationship between the Ï time series and cerebral perfusion pressure. A total of 11 intracranial hypertension episodes across three different animals were studied. RESULTS: The mean correlation between Ï angle and ICP was - 0.85 (0.15); the mean correlation with cerebral perfusion pressure was 0.92 (0.02). Significant correlation occurred at zero lag. In the absence of intracranial hypertension, the absolute value of the Ï angle was greater than 0.9 (mean 0.936 radians). However, during extreme intracranial hypertension causing cerebral circulatory arrest, the Ï angle is on average below 0.9 radians (mean 0.855 radians). CONCLUSIONS: EEG Ï angle is a promising real-time noninvasive measure of ICP/cerebral perfusion using surface electroencephalography.
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RESUMEN El aneurisma de aorta abdominal (AAA) sintomático no roto es una patología que involucra a aquellos pacientes con AAA intacto, pero que presentan dolor abdominal y/o lumbar atribuido al aneurisma. Esta forma de presentación clínica es po tencialmente mortal dado que su etiopatogenia comprende cambios agudos en la pared aórtica, incluyendo inflamación, lo que incrementa la probabilidad de ruptura inminente. Está claro que estos pacientes deben ser derivados a reparación del AAA. Sin embargo, el momento de la intervención es controvertido. Por lo tanto, el objetivo del presente trabajo fue revisar la información actualizada sobre el abordaje diagnóstico-terapéutico del AAA sintomático no roto.
ABSTRACT Symptomatic unruptured abdominal aortic aneurysm (AAA) refers to a group of patients with intact AAA but who present abdominal and/or lumbar pain attributed to the aneurysm. This form of clinical presentation is potentially fatal since its etiopathogenesis, involving acute changes in the aortic wall, including inflammation, increases the probability of impending rupture. It is clear that these patients should be referred to AAA repair. However, the timing of the intervention is contro versial. Therefore, the aim of the present work was to review updated information on the diagnostic-therapeutic approach of symptomatic unruptured AAA.
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Abstract Background: Peripheral artery disease (PAD) frequently affects multiple segments of the limbs. Contradictory data have reported worse prognosis in aortoiliac lesions, nevertheless, diabetes and chronic limb ischemia frequently affects the infrapatellar territory. Our aim was to assess the impact of infrapatellar disease in cardiovascular outcomes. Methods: We performed a retrospective, observational cohort study at a university hospital in Argentina. Electronic health records were retrospectively reviewed including symptomatic PAD patients requiring revascularization. A multivariable regression model was performed to account for confounders. The primary endpoint was a composite of hospitalizations due to chronic limb threatening ischemia (CLTI) and major amputation events between infrapatellar and suprapatellar patients. Minor amputation events, all-cause death, myocardial infarction (MI), stroke, and major cardiovascular events (MACE) were secondary endpoints. Results: From January 2014 through July 2020, a total of 309 patients were included in the analysis. 151 patients had suprapatellar disease, and 158 had infrapatellar disease. The primary composite endpoint occurred in 35 patients (22.2%) in the infrapatellar patients and 18 patients (11.9%) in the suprapatellar patients (HR = 2.16; 95% confidence interval [CI] = [1.22-3.82]; p = 0.008). Both components of the primary outcomes occurred more frequently in infrapatellar patients. Minor amputation events were more prevalent in infrapatellar patients (HR = 5.09; 95% CI = [1.47-17.6]; p = 0.010). Death, MI, stroke, and MACE events were not different among groups (all p > 0.05). Conclusion: Infrapatellar disease was an independent factor for increased hospitalization of CLTI, major and minor amputations events, compared to suprapatellar disease in symptomatic revascularized PAD patients.
Resumen Objetivo: La enfermedad vascular periférica (EVP) afecta generalmente múltiples segmentos de los miembros. Existe información contradictoria con respecto al pronóstico de pacientes con enfermedad aortoilíaca, sin embargo, la diabetes y la enfermedad critica de miembros inferiores habitualmente afecta el territorio infrapatelar. Nuestro objetivo es determinar el impacto de la afectación infrapatelar en eventos cardiovasculares. Métodos: Estudio retrospectivo, observacional en un hospital universitario de Argentina. Se revisó la historia clínica electrónica de pacientes con EVP con requerimiento de revascularización. Se generó un modelo de regresión multivariado incluyendo variables clínicamente relevantes. El punto final primario fue un combinado de hospitalización por isquemia crítica y amputaciones mayores entre pacientes con afectación infrapatelar y suprapatelar. Amputaciones menores, muerte por todas las causas, infarto agudo de miocardio (IAM), accidente cerebrovascular (ACV) y un combinado de eventos cardiovasculares (MACE) fueron los puntos secundarios. Resultados: Se reclutó un total de 309 pacientes desde enero de 2014 hasta julio de 2020. 151 pacientes presentaron enfermedad suprapatelar y 158 infrapatelar. El punto final primario ocurrió en 35 pacientes (22.2%) en el grupo infrapatelar y en 18 pacientes (11.9%) en suprapatelares (HR 2.16; intervalo de confianza 95% [1.22-3.82]; p = 0.008). Ambos componentes ocurrieron con mayor frecuencia en pacientes con afectación infrapatelar. Los eventos de amputación menor fueron mas prevalentes en pacientes con afectación infrapatelar (HR 5.09; IC95% [1.47-17.6]; p = 0.010) La mortalidad por todas las causas, IAM, ACV y MACE no fueron diferentes entre los grupos (p > 0.05). Conclusión: La enfermedad infrapatelar fue un factor independiente para mayor riesgo de hospitalización por isquemia critica, amputación mayor y menor comparado con pacientes con afectación suprapatelar en EVP sintomática revascularizada.
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Increasing interest has been shown in the subject of non-additive entropic forms during recent years, which has essentially been due to their potential applications in the area of complex systems. Based on the fact that a given entropic form should depend only on a set of probabilities, its time evolution is directly related to the evolution of these probabilities. In the present work, we discuss some basic aspects related to non-additive entropies considering their time evolution in the cases of continuous and discrete probabilities, for which nonlinear forms of Fokker-Planck and master equations are considered, respectively. For continuous probabilities, we discuss an H-theorem, which is proven by connecting functionals that appear in a nonlinear Fokker-Planck equation with a general entropic form. This theorem ensures that the stationary-state solution of the Fokker-Planck equation coincides with the equilibrium solution that emerges from the extremization of the entropic form. At equilibrium, we show that a Carnot cycle holds for a general entropic form under standard thermodynamic requirements. In the case of discrete probabilities, we also prove an H-theorem considering the time evolution of probabilities described by a master equation. The stationary-state solution that comes from the master equation is shown to coincide with the equilibrium solution that emerges from the extremization of the entropic form. For this case, we also discuss how the third law of thermodynamics applies to equilibrium non-additive entropic forms in general. The physical consequences related to the fact that the equilibrium-state distributions, which are obtained from the corresponding evolution equations (for both continuous and discrete probabilities), coincide with those obtained from the extremization of the entropic form, the restrictions for the validity of a Carnot cycle, and an appropriate formulation of the third law of thermodynamics for general entropic forms are discussed.
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Fluorescence Resonance Energy Transfer (FRET)-based approaches are unique tools for sensing the immediate surroundings and interactions of (bio)molecules. FRET imaging and Fluorescence Lifetime Imaging Microscopy (FLIM) enable the visualization of the spatial distribution of molecular interactions and functional states. However, conventional FLIM and FRET imaging provide average information over an ensemble of molecules within a diffraction-limited volume, which limits the spatial information, accuracy, and dynamic range of the observed signals. Here, an approach to obtain super-resolved FRET imaging based on single-molecule localization microscopy using an early prototype of a commercial time-resolved confocal microscope is demonstrated. DNA Points Accumulation for Imaging in Nanoscale Topography with fluorogenic probes provides a suitable combination of background reduction and binding kinetics compatible with the scanning speed of usual confocal microscopes. A single laser is used to excite the donor, a broad detection band is employed to retrieve both donor and acceptor emission, and FRET events are detected from lifetime information.
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DNA , Transferência Ressonante de Energia de Fluorescência , Transferência Ressonante de Energia de Fluorescência/métodos , Microscopia de Fluorescência/métodos , DNA/química , Microscopia Confocal , Imagem Individual de MoléculaRESUMO
Neonicotinoids are effective insecticides with specificity for invertebrate nicotinic acetylcholine receptors. Neonicotinoids are chemically stable and tend to remain in the environment for long so concerns about their neurotoxicity in humans do nothing but increase. Herein, we evaluated the chronic toxic effects of acetamiprid- and imidacloprid-based insecticides over the differentiation of human neuroblastoma SH-SY5Y cells, which were exposed to these insecticides at a concentration range similar to that applied to crop fields (0.01-0.5 mM). Both insecticides did not have acute cytotoxic effects in both non-differentiated and in staurosporine-differentiated SH-SY5Y cells cytotoxicity as measured by the MTT and vital-dye exclusion tests. However, after a chronic (7-day) treatment, only imidacloprid dose-dependently decreased the viability of SH-SY5Y cells (F(4,39) = 43.05, P < 0.001), largely when administered-during cell differentiation (F(4,39) = 51.86, P < 0.001). A well-defined dose-response curve was constructed for imidacloprid on day 4 (R2 = 0.945, EC50 = 0.14 mM). During differentiation, either imidacloprid or acetamiprid dose-dependently caused neurite branch retraction on day 3, likely because of oxidative stress, to the extent that cells turned into spheres without neurites after 7-day treatment. Despite their apparent safety, the neurodevelopmental vulnerability of SH-SY5Y neurons to the chronic exposure to imidacloprid and to a lesser extent to acetamiprid points to a neurotoxic risk for humans.
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Obtaining arrays of single nanoparticles with three-dimensional complex shapes is still an open challenge. Current nanolithography methods do not allow for the preparation of nanoparticles with complex features like nanostars. In this work, we investigate the optical printing of gold nanostars of different sizes as a function of laser wavelength and power. We found that tuning the laser to the main resonances of the nanostars in the near-infrared makes it possible to avoid nanoparticles reshaping due to plasmonic heating, enabling their deposition at the single particle level and in ordered arrays.