Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Eur J Appl Physiol ; 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39017740

RESUMEN

The purpose of this study was to investigate the effects of acute nitrate (NO3-)-rich beetroot juice ingestion on explosive and high-intensity exercise performance, oral microbiota composition, and cognitive flexibility (i.e., function), before and after maximal intermittent running exercise. Fifteen women team-sport athletes were assigned in a randomized, double-blind, crossover design to consume concentrated NO3--depleted beetroot juice (PL; 0.1 mmol NO3-) and NO3--rich beetroot juice (BR; 12.0 mmol NO3-) 2.5 h prior to performing a battery of exercise performance tasks and cognitive testing before and after the Yo-Yo intermittent recovery level 1 (YYIR1) running test. Resting plasma [NO3-] and plasma nitrite ([NO2-]) were elevated following BR (P < 0.001). BR did not impact global composition or relative abundance of taxa in the oral microbiome (P > 0.05) or cognitive flexibility before or after exercise (P > 0.05). There was no significant difference in performance during 20-m (PRE, PL: 4.38 ± 0.27 vs. BR: 4.38 ± 0.32 s; POST, PL: 4.45 ± 0.29 vs. BR: 4.43 ± 0.35 s) and 10-m sprints (PRE, PL 2.78 ± 0.15 vs. BR 2.79 ± 0.18 s; POST, PL: 2.82 ± 0.16 vs. BR: 2.81 ± 0.19 s), isokinetic handgrip dynamometry, medicine ball throw, horizontal countermovement jump, or YYIR1 (PL: 355 ± 163 m vs. BR: 368 ± 184 m) between BR and PL (P > 0.05). These findings indicate that acute dietary NO3- may not influence the oral microbiome, explosive and high-intensity exercise performance, or cognitive function in women team-sport athletes.

2.
Nano Lett ; 19(8): 5077-5085, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31283241

RESUMEN

Atomically thin two-dimensional (2D) materials are promising candidates for sub-10 nm transistor channels due to their ultrathin body thickness, which results in strong electrostatic gate control. Properly scaling a transistor technology requires reducing both the channel length (distance from source to drain) and the contact length (distance that source and drain interface with semiconducting channel). Contact length scaling remains an unresolved epidemic for transistor scaling, affecting devices from all semiconductors-silicon to 2D materials. Here, we show that clean edge contacts to 2D MoS2 can provide immunity to the contact-scaling problem, with performance that is independent of contact length down to the 20 nm regime. Using a directional ion beam, in situ edge contacts of various metal-MoS2 interfaces are studied. Characterization of the intricate edge interface using cross-sectional electron microscopy reveals distinct morphological effects on the MoS2 depending on its thickness-from monolayer to few-layer films. The in situ edge contacts also exhibit an order of magnitude higher performance compared to the best-reported ex situ metal edge contacts. Our work provides experimental evidence for a solution to contact scaling in transistors, using 2D materials with clean edge contact interfaces, opening a new way of designing devices with 2D materials.

3.
Stem Cells ; 35(5): 1259-1272, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28181347

RESUMEN

Mesenchymal stromal cells (MSCs) are believed to mobilize from the bone marrow in response to inflammation and injury, yet the effects of egress into the vasculature on MSC function are largely unknown. Here we show that wall shear stress (WSS) typical of fluid frictional forces present on the vascular lumen stimulates antioxidant and anti-inflammatory mediators, as well as chemokines capable of immune cell recruitment. WSS specifically promotes signaling through NFκB-COX2-prostaglandin E2 (PGE2 ) to suppress tumor necrosis factor-α (TNF-α) production by activated immune cells. Ex vivo conditioning of MSCs by WSS improved therapeutic efficacy in a rat model of traumatic brain injury, as evidenced by decreased apoptotic and M1-type activated microglia in the hippocampus. These results demonstrate that force provides critical cues to MSCs residing at the vascular interface which influence immunomodulatory and paracrine activity, and suggest the potential therapeutic use of force for MSC functional enhancement. Stem Cells 2017;35:1259-1272.


Asunto(s)
Células de la Médula Ósea/citología , Células de la Médula Ósea/inmunología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/inmunología , Administración Intravenosa , Animales , Antiinflamatorios/metabolismo , Fenómenos Biomecánicos , Reactores Biológicos , Lesiones Traumáticas del Encéfalo/patología , Lesiones Traumáticas del Encéfalo/terapia , Ciclooxigenasa 2/metabolismo , Dinoprostona/biosíntesis , Humanos , Inmunomodulación , Inflamación/patología , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/metabolismo , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Fenotipo , Ratas , Reología , Transducción de Señal , Estrés Mecánico
4.
Nano Lett ; 17(8): 4801-4806, 2017 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-28691824

RESUMEN

It has been shown that a ferroelectric material integrated into the gate stack of a transistor can create an effective negative capacitance (NC) that allows the device to overcome "Boltzmann tyranny". While this switching below the thermal limit has been observed with Si-based NC field-effect transistors (NC-FETs), the adaptation to 2D materials would enable a device that is scalable in operating voltage as well as size. In this work, we demonstrate sustained sub-60 mV/dec switching, with a minimum subthreshold swing (SS) of 6.07 mV/dec (average of 8.03 mV/dec over 4 orders of magnitude in drain current), by incorporating hafnium zirconium oxide (HfZrO2 or HZO) ferroelectric into the gate stack of a MoS2 2D-FET. By first fabricating and characterizing metal-ferroelectric-metal capacitors, the MoS2 is able to be transferred directly on top and characterized with both a standard and a negative capacitance gate stack. The 2D NC-FET exhibited marked enhancement in low-voltage switching behavior compared to the 2D-FET on the same MoS2 channel, reducing the SS by 2 orders of magnitude. A maximum internal voltage gain of ∼28× was realized with ∼12 nm thick HZO. Several unique dependencies were observed, including threshold voltage (Vth) shifts in the 2D NC-FET (compared to the 2D-FET) that correlate with source/drain overlap capacitance and changes in HZO (ferroelectric) and HfO2 (dielectric) thicknesses. Remarkable sub-60 mV/dec switching was obtained from 2D NC-FETs of various sizes and gate stack thicknesses, demonstrating great potential for enabling size- and voltage-scalable transistors.

5.
J Bacteriol ; 198(2): 237-47, 2016 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-26483523

RESUMEN

UNLABELLED: Cystic fibrosis (CF) is a human genetic disorder which results in a lung environment that is highly conducive to chronic microbial infection. Over the past decade, deep-sequencing studies have demonstrated that the CF lung can harbor a highly diverse polymicrobial community. We expanded our existing in vitro model of Pseudomonas aeruginosa biofilm formation on CF-derived airway cells to include this broader set of CF airway colonizers to investigate their contributions to CF lung disease, particularly as they relate to the antibiotic response of the population. Using this system, we identified an interspecies interaction between P. aeruginosa, a bacterium associated with declining lung function and worsening disease, and Streptococcus constellatus, a bacterium correlated with the onset of pulmonary exacerbations in CF patients. The growth rate and cytotoxicity of S. constellatus 7155 and P. aeruginosa PA14 were unchanged when grown together as mixed biofilms in the absence of antibiotics. However, the addition of tobramycin, the frontline maintenance therapy antibiotic for individuals with CF, to a mixed biofilm of S. constellatus 7155 and P. aeruginosa PA14 resulted in enhanced S. constellatus biofilm formation. Through a candidate genetic approach, we showed that P. aeruginosa rhamnolipids were reduced upon tobramycin exposure, allowing for S. constellatus 7155 biofilm enhancement, and monorhamnolipids were sufficient to reduce S. constellatus 7155 biofilm viability in the absence of tobramycin. While the findings presented here are specific to a biofilm of S. constellatus 7155 and P. aeruginosa PA14, they highlight the potential of polymicrobial interactions to impact antibiotic tolerance in unanticipated ways. IMPORTANCE: Deep-sequencing studies have demonstrated that the CF lung can harbor a diverse polymicrobial community. By recapitulating the polymicrobial communities observed in the CF lung and identifying mechanisms of interspecies interactions, we have the potential to select the best therapy for a given bacterial community and reveal potential opportunities for novel therapeutic interventions. Using an in vitro model of bacterial infection on CF airway cells, we tested how a particular polymicrobial community grows, damages human cells, and responds to antibiotics in single and mixed infections. We describe here the mechanism of an interspecies interaction between two pathogens in the CF lung, P. aeruginosa and S. constellatus, which is potentiated by a commonly prescribed antibiotic, tobramycin.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Fibrosis Quística/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/fisiología , Streptococcus constellatus/fisiología , Tobramicina/farmacología , Antibacterianos/farmacología , Técnicas Bacteriológicas , Técnicas de Cocultivo , Glucolípidos/metabolismo , Humanos , Streptococcus constellatus/efectos de los fármacos
6.
BMC Public Health ; 16: 946, 2016 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-27604549

RESUMEN

BACKGROUND: Individuals with chronic health conditions or low socioeconomic status (SES) are more vulnerable to the health impacts of climate change. Health communication can provide information on the management of these impacts. This study tested, among vulnerable audiences, whether viewing targeted materials increases knowledge about the health impacts of climate change and strength of climate change beliefs, and whether each are associated with stronger intentions to practice recommended behaviors. METHODS: Low-SES respondents with chronic conditions were recruited for an online survey in six cities. Respondents were shown targeted materials illustrating the relationship between climate change and chronic conditions. Changes in knowledge and climate change beliefs (pre- and post-test) and behavioral intentions (post-test only) were tested using McNemar tests of marginal frequencies of two binary outcomes or paired t-tests, and multivariable linear regression. Qualitative interviews were conducted among target audiences to triangulate survey findings and make recommendations on the design of messages. RESULTS: Respondents (N = 122) reflected the target population regarding income, educational level and prevalence of household health conditions. (1) Knowledge. Significant increases in knowledge were found regarding: groups that are most vulnerable to heat (children [p < 0.001], individuals with heart disease [p < 0.001], or lung disease [p = 0.019]); and environmental conditions that increase allergy-producing pollen (increased heat [p = 0.003], increased carbon dioxide [p < 0.001]). (2) Strength of certainty that climate change is happening increased significantly between pre- and post-test (p < 0.001), as did belief that climate change affected respondents' health (p < 0.001). (3) Behavioral intention. At post-test, higher knowledge of heat vulnerabilities and environmental conditions that trigger pollen allergies were associated with greater behavioral intention scores (p = 0.001 and p = 0.002, respectively). In-depth interviews (N = 15) revealed that vulnerable audiences are interested in immediate-term advice on health management and protective behaviors related to their chronic conditions, but took less notice of messages about collective action to slow or stop climate change. Respondents identified both appealing and less favorable design elements in the materials. CONCLUSIONS: Individuals who are vulnerable to the health effects of climate change benefit from communication materials that explain, using graphics and concise language, how climate change affects health conditions and how to engage in protective adaptation behaviors.


Asunto(s)
Enfermedad Crónica/psicología , Cambio Climático , Comunicación en Salud/métodos , Poblaciones Vulnerables/psicología , Adaptación Psicológica , Adolescente , Adulto , Escolaridad , Femenino , Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Renta , Intención , Modelos Lineales , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Clase Social , Encuestas y Cuestionarios , Adulto Joven
7.
Int J Technol Assess Health Care ; 32(4): 203-211, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27719689

RESUMEN

OBJECTIVES: Kids in Control OF Food (KICk-OFF) is a 5-day structured education program for 11- to 16-year-olds with type 1 diabetes mellitus (T1DM) who are using multiple daily insulin injections. This study evaluates the cost-effectiveness of the KICk-OFF education program compared with the usual care using data from the KICk-OFF trial. METHODS: The short-term within-trial analysis covers the 2-year postintervention period. Data on glycated hemoglobin (HbA1c), severe hypoglycemia, and diabetic ketoacidosis (DKA) were collected over a 2-year follow-up period. Sub-group analyses have been defined on the basis of baseline HbA1c being below 7.5 percent (58.5 mmol/mol) (low group), between 7.5 percent and 9.5 percent (80.3 mmol/mol) (medium group), and over 9.5 percent (high group). The long-term cost-effectiveness evaluation has been conducted by using The Sheffield Type 1 Diabetes Policy Model, which is a patient-level simulation model on T1DM. It includes long-term microvascular (retinopathy, neuropathy, and nephropathy) and macrovascular (myocardial infarction, stroke, revascularization, and angina) diabetes-related complications and acute adverse events (severe hypoglycemia and DKA). RESULTS: The most favorable within-trial scenario for the KICk-OFF arm led to an incremental cost-effectiveness ratio (ICER) of £23,688 (base year 2009) with a cost-effectiveness probability of 41.3 percent. Simulating the long-term complications using the full cohort data, the mean ICER for the base case was £28,813 (base year 2011) and the probability of the KICk-OFF intervention being cost-effective at £20,000/QALY threshold was 42.6 percent, with considerable variation due to treatment effect duration. For the high HbA1c sub-group, the KICk-OFF arm was "dominant" (meaning it provided better health gains at lower costs than usual care) over the usual care arm in each scenario considered. CONCLUSIONS: For the whole study population, the cost-effectiveness of KICk-OFF depends on the assumption for treatment effect duration. For the high baseline HbA1c sub-group, KICk-OFF arm was estimated to be dominant over the usual care arm regardless of the assumption on the treatment effect duration.


Asunto(s)
Complicaciones de la Diabetes/prevención & control , Diabetes Mellitus Tipo 1/terapia , Dieta , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Educación del Paciente como Asunto/organización & administración , Adolescente , Niño , Simulación por Computador , Análisis Costo-Beneficio , Complicaciones de la Diabetes/economía , Diabetes Mellitus Tipo 1/economía , Cetoacidosis Diabética/prevención & control , Femenino , Hemoglobina Glucada , Humanos , Hipoglucemia/prevención & control , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/efectos adversos , Insulina/administración & dosificación , Insulina/efectos adversos , Masculino , Modelos Econométricos , Educación del Paciente como Asunto/economía , Calidad de Vida , Años de Vida Ajustados por Calidad de Vida
8.
Cleft Palate Craniofac J ; 53(2): e34-44, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-25658963

RESUMEN

Objective To gather data from relevant experimental and observational studies to determine the relationship between micrognathia and cleft palate. The goal is to raise awareness and motivate clinicians to consider the cause and effect relationship when confronted with patients with cleft palate, even if there is no clearly noticeable mandibular abnormality. Design Several electronic databases were systematically examined to find articles for this review, using search terms including "cleft palate," "micrognathia," "tongue," and "airway obstruction." PubMed was the source of all the articles chosen to be included. Exclusion criteria included case reports, articles focused on treatment options, and articles only tangentially related to cleft palate and/or micrognathia. Results A total of 930 articles were screened for relevance, and 82 articles were chosen for further analysis. Evidence gathered in this review includes a variety of etiological factors that are causative or associated with both micrognathia and cleft palate. Observational studies relating the two abnormalities are also included. Much of the included literature recognizes a cause-and-effect relationship between micrognathia and cleft palate. Conclusion On the basis of the published data, we suggest that micrognathia does induce cleft palate in humans and animals. With knowledge of this causative relationship, clinicians should consider the importance of gathering cephalometric data on the mandibles and tongues of patients presenting with isolated cleft palate to determine whether they have micrognathia as well. With more data, patterns may emerge that could give insight into the complex etiology of nonsyndromic cleft palate.


Asunto(s)
Fisura del Paladar/etiología , Micrognatismo/complicaciones , Animales , Cefalometría , Humanos
9.
J Neurosci ; 34(23): 8021-31, 2014 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-24899723

RESUMEN

Mutations in the metallo-protein Cu/Zn-superoxide dismutase (SOD1) cause amyotrophic lateral sclerosis (ALS) in humans and an expression level-dependent phenotype in transgenic rodents. We show that oral treatment with the therapeutic agent diacetyl-bis(4-methylthiosemicarbazonato)copper(II) [Cu(II)(atsm)] increased the concentration of mutant SOD1 (SOD1G37R) in ALS model mice, but paradoxically improved locomotor function and survival of the mice. To determine why the mice with increased levels of mutant SOD1 had an improved phenotype, we analyzed tissues by mass spectrometry. These analyses revealed most SOD1 in the spinal cord tissue of the SOD1G37R mice was Cu deficient. Treating with Cu(II)(atsm) decreased the pool of Cu-deficient SOD1 and increased the pool of fully metallated (holo) SOD1. Tracking isotopically enriched (65)Cu(II)(atsm) confirmed the increase in holo-SOD1 involved transfer of Cu from Cu(II)(atsm) to SOD1, suggesting the improved locomotor function and survival of the Cu(II)(atsm)-treated SOD1G37R mice involved, at least in part, the ability of the compound to improve the Cu content of the mutant SOD1. This was supported by improved survival of SOD1G37R mice that expressed the human gene for the Cu uptake protein CTR1. Improving the metal content of mutant SOD1 in vivo with Cu(II)(atsm) did not decrease levels of misfolded SOD1. These outcomes indicate the metal content of SOD1 may be a greater determinant of the toxicity of the protein in mutant SOD1-associated forms of ALS than the mutations themselves. Improving the metal content of SOD1 therefore represents a valid therapeutic strategy for treating ALS caused by SOD1.


Asunto(s)
Esclerosis Amiotrófica Lateral , Neuronas Motoras/efectos de los fármacos , Mutación/genética , Compuestos Organometálicos/administración & dosificación , Superóxido Dismutasa/genética , Tiosemicarbazonas/administración & dosificación , Administración Oral , Factores de Edad , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/mortalidad , Esclerosis Amiotrófica Lateral/patología , Animales , Proteínas de Transporte de Catión/genética , Cromatografía en Gel , Complejos de Coordinación , Transportador de Cobre 1 , Modelos Animales de Enfermedad , Humanos , Locomoción/efectos de los fármacos , Locomoción/genética , Ratones , Ratones Transgénicos , Fenotipo , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismo , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa-1
10.
Inorg Chem ; 54(19): 9594-610, 2015 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-26375592

RESUMEN

With the aim of preparing hypoxia-selective imaging and therapeutic agents, technetium(I) and rhenium(I) tricarbonyl complexes with pyridylhydrazone, dipyridylamine, and pyridylaminocarboxylate ligands containing nitrobenzyl or nitroimidazole functional groups have been prepared. The rhenium tricarbonyl complexes were synthesized with short reaction times using microwave irradiation. Rhenium tricarbonyl complexes with deprotonated p-nitrophenyl pyridylhydrazone ligands are luminescent, and this has been used to track their uptake in HeLa cells using confocal fluorescent microscopy. Selected rhenium tricarbonyl complexes displayed higher uptake in hypoxic cells when compared to normoxic cells. A (99m)Tc tricarbonyl complex with a dipyridylamine ligand bearing a nitroimidazole functional group is stable in human serum and was shown to localize in a human renal cell carcinoma (RCC; SK-RC-52) tumor in a mouse.


Asunto(s)
Hipoxia , Compuestos Organometálicos/farmacocinética , Renio/farmacocinética , Tecnecio/farmacocinética , Animales , Línea Celular Tumoral , Diagnóstico por Imagen , Técnicas Electroquímicas , Células HeLa , Humanos , Ligandos , Luminiscencia , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Microscopía Fluorescente , Modelos Moleculares , Estructura Molecular , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/química , Renio/química , Tecnecio/química , Distribución Tisular
11.
Inorg Chem ; 54(19): 9556-67, 2015 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-26397162

RESUMEN

The intracellular distribution of fluorescently labeled copper and zinc bis(thiosemicarbazonato) complexes was investigated in M17 neuroblastoma cells and primary cortical neurons with a view to providing insights into the neuroprotective activity of a copper bis(thiosemicarbazonato) complex known as Cu(II)(atsm). Time-resolved fluorescence measurements allowed the identification of the Cu(II) and Zn(II) complexes as well as the free ligand inside the cells by virtue of the distinct fluorescence lifetime of each species. Confocal fluorescent microscopy of cells treated with the fluorescent copper(II)bis(thiosemicarbazonato) complex revealed significant fluorescence associated with cytoplasmic puncta that were identified to be lysosomes in primary cortical neurons and both lipid droplets and lysosomes in M17 neuroblastoma cells. Fluorescence lifetime imaging microscopy confirmed that the fluorescence signal emanating from the lipid droplets could be attributed to the copper(II) complex but also that some degree of loss of the metal ion led to diffuse cytosolic fluorescence that could be attributed to the metal-free ligand. The accumulation of the copper(II) complex in lipid droplets could be relevant to the neuroprotective activity of Cu(II)(atsm) in models of amyotrophic lateral sclerosis and Parkinson's disease.


Asunto(s)
Complejos de Coordinación/farmacocinética , Cobre/química , Fluorescencia , Tiosemicarbazonas/química , Zinc/química , Línea Celular Tumoral , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Humanos , Modelos Moleculares , Estructura Molecular , Espectrometría de Fluorescencia , Factores de Tiempo , Distribución Tisular
12.
Interv Cardiol Clin ; 13(3): 421-430, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38839174

RESUMEN

Since PDA stenting was first attempted in the early 1990s, significant technical advancements have improved outcomes and some centers have even transitioned to exclusive PDA stenting for all infants with duct-dependent pulmonary circulation. In addition to its use in infants with duct-dependent pulmonary circulation, PDA stenting has also been adapted as a percutaneous palliative option for suprasystemic pulmonary arterial hypertension and as a component of the hybrid procedure. In this article, the authors aim to review indications and outcomes for PDA stenting, describe the procedure, and discuss future directions.


Asunto(s)
Conducto Arterioso Permeable , Stents , Humanos , Conducto Arterioso Permeable/cirugía , Cateterismo Cardíaco/métodos , Cuidados Paliativos/métodos , Resultado del Tratamiento
13.
Front Nutr ; 10: 1217192, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37485396

RESUMEN

This study tested the hypothesis that co-ingesting nitrate (NO3-)-rich beetroot juice (BR) and pomegranate powder (POM) would enhance neuromuscular performance during vertical countermovement jumps, explosive kneeling countermovement push-ups, and back squats compared to BR ingestion alone. Fifteen recreationally-active males were assigned in a double-blind, randomized, crossover design, to supplement in 3 conditions: (1) NO3--depleted beetroot juice (PL; 0.10 mmol NO3-) with two empty gelatin capsules; (2) NO3--rich beetroot juice (BR; 11.8 mmol NO3-) with two empty gelatin capsules, and (3) BR with 1,000 mg of POM powder in two capsules (BR + POM). Participants completed 5 countermovement jumps and 5 kneeling countermovement push-ups interspersed by 1 min of recovery. Subsequently, participants performed 2 sets of 2 × 70% one-repetition maximum back squats, interspersed by 2 min of recovery. Plasma [NO3-] and nitrite ([NO2-]) were elevated following BR and BR + POM compared with PL and POM (p < 0.001) with no differences between BR and BR + POM (p > 0.05) or PL and POM (p > 0.05). Peak power during countermovement jumps increased by 3% following BR compared to BR + POM (88.50 ± 11.46 vs. 85.80 ± 10.14 W/Kg0.67, p = 0.009) but not PL (88.50 ± 11.46 vs. 85.58 ± 10.05 W/Kg0.67, p = 0.07). Neuromuscular performance was not different between conditions during explosive kneeling push-ups and back squats (p > 0.05). These data provide insight into the efficacy of NO3- to modulate explosive resistance exercise performance and indicate that supplementing with BR alone or combined with POM has limited ergogenic potential on resistance exercise. Furthermore, caution is required when combining BR with POM, as this could compromise aspects of resistance exercise performance, at least when compared to BR ingested independently.

14.
J Cancer Res Clin Oncol ; 149(15): 14125-14136, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37552307

RESUMEN

PURPOSE: Anti-PD-1 therapy provides clinical benefit in 40-50% of patients with relapsed and/or metastatic head and neck squamous cell carcinoma (RM-HNSCC). Selection of anti- PD-1 therapy is typically based on patient PD-L1 immunohistochemistry (IHC) which has low specificity for predicting disease control. Therefore, there is a critical need for a clinical biomarker that will predict clinical benefit to anti-PD-1 treatment with high specificity. METHODS: Clinical treatment and outcomes data for 103 RM-HNSCC patients were paired with RNA-sequencing data from formalin-fixed patient samples. Using logistic regression methods, we developed a novel biomarker classifier based on expression patterns in the tumor immune microenvironment to predict disease control with monotherapy PD-1 inhibitors (pembrolizumab and nivolumab). The performance of the biomarker was internally validated using out-of-bag methods. RESULTS: The biomarker significantly predicted disease control (65% in predicted non-progressors vs. 17% in predicted progressors, p < 0.001) and was significantly correlated with overall survival (OS; p = 0.004). In addition, the biomarker outperformed PD-L1 IHC across numerous metrics including sensitivity (0.79 vs 0.64, respectively; p = 0.005) and specificity (0.70 vs 0.61, respectively; p = 0.009). CONCLUSION: This novel assay uses tumor immune microenvironment expression data to predict disease control and OS with high sensitivity and specificity in patients with RM-HNSCC treated with anti-PD-1 monotherapy.

15.
J Bacteriol ; 194(14): 3651-60, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22563048

RESUMEN

Streptococcus pneumoniae is a major causative agent of otitis media, pneumonia, bacteremia, and meningitis. Pneumolysin (Ply), a member of the cholesterol-dependent cytolysins (CDCs), is produced by virtually all clinical isolates of S. pneumoniae, and ply mutant strains are severely attenuated in mouse models of colonization and infection. In contrast to all other known members of the CDC family, Ply lacks a signal peptide for export outside the cell. Instead, Ply has been hypothesized to be released upon autolysis or, alternatively, via a nonautolytic mechanism that remains undefined. We show that an exogenously added signal sequence is not sufficient for Sec-dependent Ply secretion in S. pneumoniae but is sufficient in the surrogate host Bacillus subtilis. Previously, we showed that Ply is localized primarily to the cell wall compartment in the absence of detectable cell lysis. Here we show that Ply released by autolysis cannot reassociate with intact cells, suggesting that there is a Ply export mechanism that is coupled to cell wall localization of the protein. This putative export mechanism is capable of secreting a related CDC without its signal sequence. We show that B. subtilis can export Ply, suggesting that the export pathway is conserved. Finally, through truncation and domain swapping analyses, we show that export is dependent on domain 2 of Ply.


Asunto(s)
Streptococcus pneumoniae/metabolismo , Estreptolisinas/metabolismo , Secuencia de Aminoácidos , Bacillus subtilis , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Bacteriólisis , Secuencia de Bases , ADN Bacteriano/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , ARN Bacteriano/genética , ARN Bacteriano/metabolismo , Estreptolisinas/genética
16.
Nutrients ; 14(18)2022 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-36145080

RESUMEN

The purpose of the current study was to assess the effects of acute and short-term nitrate (NO3−)-rich beetroot juice (BR) supplementation on performance outcomes and muscle oxygenation during bench press and back squat exercise. Fourteen recreationally active males were assigned in a randomized, double-blind, crossover design to supplement for 4 days in two conditions: (1) NO3−-depleted beetroot juice (PL; 0.10 mmol NO3− per day) and (2) BR (11.8 mmol NO3− per day). On days 1 and 4 of the supplementation periods, participants completed 2 sets of 2 × 70%1RM interspersed by 2 min of recovery, followed by one set of repetitions-to-failure (RTF) at 60%1RM for the determination of muscular power, velocity, and endurance. Quadriceps and pectoralis major tissue saturation index (TSI) were measured throughout exercise. Plasma [NO3−] and nitrite ([NO2−]) were higher after 1 and 4 days of supplementation with BR compared to PL (p < 0.05). Quadriceps and pectoralis major TSI were not different between conditions (p > 0.05). The number of RTF in bench press was 5% greater after acute BR ingestion compared to PL (PL: 23 ± 4 vs. BR: 24 ± 5, p < 0.05). There were no differences between BR and PL for RTF for back squat or power and velocity for back squat or bench press (p > 0.05). These data improve understanding on the ergogenic potential of BR supplementation during resistance exercise.


Asunto(s)
Beta vulgaris , Entrenamiento de Fuerza , Estudios Cruzados , Suplementos Dietéticos , Método Doble Ciego , Humanos , Masculino , Nitratos/farmacología , Nitritos , Dióxido de Nitrógeno , Óxidos de Nitrógeno , Músculo Cuádriceps
17.
Inorg Chem ; 50(19): 9594-605, 2011 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-21882803

RESUMEN

Copper (Cu) bis(thiosemicarbazonato) metal complexes [Cu(II)(btsc)s] have unique tumor-imaging and treatment properties and more recently have revealed potent neuroprotective actions in animal and cell models of neurodegeneration. However, despite the continued development of Cu(II)(btsc)s as potential therapeutics or diagnostic agents, little is known of the mechanisms involved in cell uptake, subcellular trafficking, and efflux of this family of compounds. Because of their high lipophilicity, it has been assumed that cellular accumulation is through passive diffusion, although this has not been analyzed in detail. The role of efflux pathways in cell homeostasis of the complexes is also largely unknown. In the present study, we investigated the cellular accumulation of the Cu(II)(btsc) complexes Cu(II)(gtsm) and Cu(II)(atsm) in human neuronal (M17) and glial (U87MG) cell lines under a range of conditions. Collectively, the data strongly suggested that Cu(II)(gtsm) and Cu(II)(atsm) may be taken into these cells by combined passive and facilitated (protein-carrier-mediated) mechanisms. This was supported by strong temperature-dependent changes to the uptake of the complexes and the influence of the cell surface protein on Cu accumulation. We found no evidence to support a role for copper-transporter 1 in accumulation of the compounds. Importantly, our findings also demonstrated that Cu from both Cu(II)(gtsm) and Cu(II)(atsm) was rapidly effluxed from the cells through active mechanisms. Whether this was in the form of released ionic Cu or as an intact metal complex is not known. However, this finding highlighted the difficulty of trying to determine the uptake mechanism of metal complexes when efflux is occurring concomitantly. These findings are the first detailed exploration of the cellular accumulation mechanisms of Cu(II)(btsc)s. The study delineates strategies to investigate the uptake and efflux mechanisms of metal complexes in cells, while highlighting specific difficulties and challenges that need to be considered before drawing definitive conclusions.


Asunto(s)
Complejos de Coordinación/farmacocinética , Cobre/fisiología , Tiosemicarbazonas/farmacocinética , Línea Celular Tumoral , Complejos de Coordinación/farmacología , Cobre/farmacología , Endocitosis/fisiología , Humanos , Immunoblotting , Espectrometría de Masas , Proteínas de la Membrana/metabolismo , Neuroglía/metabolismo , Neuronas , Tiosemicarbazonas/farmacología
18.
Int J Radiat Oncol Biol Phys ; 110(2): 396-402, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33359567

RESUMEN

PURPOSE: De-escalated treatment for human papillomavirus (HPV)+ oropharynx squamous cell carcinoma (OPSCC) has shown promising initial results. Health-care policy is increasingly focusing on high-value care. This analysis compares the cost of care for HPV+ OPSCC treated with definitive chemoradiation (CRT), surgery and adjuvant radiation (RT), and surgery and de-escalated CRT on MC1273. METHODS AND MATERIALS: MC1273 is a prospective, phase 2 study evaluating adjuvant CRT to 30 to 36 Gy plus docetaxel for HPV+ OPSCC after surgery for high-risk patients. Matched standard-of-care control groups were retrospectively identified for patients treated with definitive CRT or adjuvant RT. Standardized costs were evaluated before radiation, during treatment (during RT), and at short-term (6 month) and long-term (7-24 month) follow-up periods. RESULTS: A total of 56 definitive CRT, 101 adjuvant RT, and 66 MC1273 patients were included. The CRT arm had more T3-4 disease (63% vs 17-21%) and higher N2c-N3 disease (52% vs 20-24%) vs both other groups. The total treatment costs in the CRT, adjuvant RT, and MC1273 groups were $47,763 (standard deviation [SD], $19,060], $57,845 (SD, $17,480), and $46,007 (SD, $9019), respectively, and the chemotherapy and/or RT costs were $39,936 (SD, $18,480), $26,603 (SD, $12,542), and $17,864 (SD, $3288), respectively. The per-patient, per-month, average short-term follow-up costs were $3860 (SD, $10,525), $1072 (SD, $996), and $972 (SD, $833), respectively, and the long-term costs were $978 (SD, $2294), $485 (SD, $1156), and $653 (SD, $1107), respectively. After adjustment for age, T-stage, and N-stage, treatment costs remained lower for CRT and MC1273 versus adjuvant RT ($45,450 and $47,114 vs $58,590, respectively; P < .001), whereas the total per-patient, per-month follow-up costs were lower in the MC1273 study group and adjuvant RT versus CRT ($853 and $866 vs $2030, respectively; P = .03). CONCLUSIONS: MC1273 resulted in 10% and 20% reductions in global costs compared with standard-of-care adjuvant RT and definitive CRT treatments. Substantial cost savings may be an added benefit to the already noted low toxicity and maintained quality of life of treatment per MC1273.


Asunto(s)
Quimioradioterapia/economía , Neoplasias Orofaríngeas/terapia , Infecciones por Papillomavirus/complicaciones , Radioterapia Adyuvante/economía , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Antineoplásicos/economía , Antineoplásicos/uso terapéutico , Quimioradioterapia/efectos adversos , Quimioradioterapia/estadística & datos numéricos , Quimioradioterapia Adyuvante/efectos adversos , Quimioradioterapia Adyuvante/economía , Quimioradioterapia Adyuvante/estadística & datos numéricos , Ahorro de Costo/economía , Costos y Análisis de Costo , Docetaxel/economía , Docetaxel/uso terapéutico , Fraccionamiento de la Dosis de Radiación , Femenino , Estudios de Seguimiento , Hospitalización/economía , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Orofaríngeas/patología , Neoplasias Orofaríngeas/virología , Periodo Posoperatorio , Estudios Prospectivos , Calidad de Vida , Radioterapia Adyuvante/efectos adversos , Radioterapia Adyuvante/métodos , Radioterapia Adyuvante/estadística & datos numéricos , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/virología , Procedimientos Quirúrgicos Operativos/economía
19.
J Biol Inorg Chem ; 15(2): 225-35, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19771456

RESUMEN

The synthesis of new copper(II) bis(thiosemicarbazonato) complexes with an appended pyrene chromophore and their zinc(II) analogues is reported. The new proligands and their copper(II) and zinc(II) complexes were characterised by a combination of NMR, EPR, high performance liquid chromatography, mass spectrometry, electronic spectroscopy and electrochemical measurements. The new copper(II) complexes are fluorescent as a consequence of an appended pyrene substituent that is separated from the sulphur coordinating to the metal ion by five bonds. The emission from the pyrene substituent is concentration- and solvent-dependent with characteristic formation of excimer aggregates. A radioactive (64)Cu complex has been prepared. Cell permeability, intracellular distribution and importantly the ability to cross the nuclear membrane to target DNA were investigated using confocal fluorescence microscopy in a human cancer cell line under normal oxygen conditions and hypoxic conditions. In both cases, there was no evidence of uptake of the copper(II) bis(thiosemicarbazonato) complexes in the area of the cell nucleus.


Asunto(s)
Cobre/química , Colorantes Fluorescentes/química , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacocinética , Tiosemicarbazonas/química , Zinc/química , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Radioisótopos de Cobre/química , Humanos , Marcaje Isotópico , Microscopía Fluorescente , Estructura Molecular , Compuestos Organometálicos/química , Pirenos/química , Distribución Tisular
20.
J Bacteriol ; 191(7): 2163-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19168620

RESUMEN

Streptococcus pneumoniae is the causative agent of multiple diseases, including otitis media, pneumonia, bacteremia, and meningitis. Pneumolysin (Ply), a member of the cholesterol-dependent cytolytic pore-forming toxins, is produced by virtually all clinical isolates of S. pneumoniae, and strains in which the Ply gene has been deleted are severely attenuated in mouse models of infection. In contrast to all other members of the cholesterol-dependent cytolysin family, Ply lacks a signal peptide for export. Instead, Ply has been hypothesized to be released upon autolysis or, alternatively, via a nonautolytic mechanism that remains ill defined. We determined by use of cell fractionation and Western blotting that, during in vitro growth, exported Ply is localized primarily to the cell wall compartment in 18 different serotypes in the absence of detectable cell lysis. Hemolytic assays revealed that this cell wall-localized Ply is active. Additionally, cell wall-localized Ply is accessible to extracellular protease and is detergent releasable.


Asunto(s)
Pared Celular/metabolismo , Infecciones Neumocócicas/microbiología , Streptococcus pneumoniae/metabolismo , Estreptolisinas/metabolismo , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pared Celular/genética , Eritrocitos/microbiología , Hemolíticos/metabolismo , Humanos , Transporte de Proteínas , Ovinos , Streptococcus pneumoniae/genética , Estreptolisinas/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA