Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Cell ; 186(1): 112-130.e20, 2023 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-36580912

RESUMEN

How SARS-CoV-2 penetrates the airway barrier of mucus and periciliary mucins to infect nasal epithelium remains unclear. Using primary nasal epithelial organoid cultures, we found that the virus attaches to motile cilia via the ACE2 receptor. SARS-CoV-2 traverses the mucus layer, using motile cilia as tracks to access the cell body. Depleting cilia blocks infection for SARS-CoV-2 and other respiratory viruses. SARS-CoV-2 progeny attach to airway microvilli 24 h post-infection and trigger formation of apically extended and highly branched microvilli that organize viral egress from the microvilli back into the mucus layer, supporting a model of virus dispersion throughout airway tissue via mucociliary transport. Phosphoproteomics and kinase inhibition reveal that microvillar remodeling is regulated by p21-activated kinases (PAK). Importantly, Omicron variants bind with higher affinity to motile cilia and show accelerated viral entry. Our work suggests that motile cilia, microvilli, and mucociliary-dependent mucus flow are critical for efficient virus replication in nasal epithelia.


Asunto(s)
COVID-19 , Sistema Respiratorio , SARS-CoV-2 , Humanos , Cilios/fisiología , Cilios/virología , COVID-19/virología , Sistema Respiratorio/citología , Sistema Respiratorio/virología , SARS-CoV-2/fisiología , Microvellosidades/fisiología , Microvellosidades/virología , Internalización del Virus , Células Epiteliales/fisiología , Células Epiteliales/virología
2.
Cell ; 184(25): 6037-6051.e14, 2021 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-34852237

RESUMEN

RNA viruses generate defective viral genomes (DVGs) that can interfere with replication of the parental wild-type virus. To examine their therapeutic potential, we created a DVG by deleting the capsid-coding region of poliovirus. Strikingly, intraperitoneal or intranasal administration of this genome, which we termed eTIP1, elicits an antiviral response, inhibits replication, and protects mice from several RNA viruses, including enteroviruses, influenza, and SARS-CoV-2. While eTIP1 replication following intranasal administration is limited to the nasal cavity, its antiviral action extends non-cell-autonomously to the lungs. eTIP1 broad-spectrum antiviral effects are mediated by both local and distal type I interferon responses. Importantly, while a single eTIP1 dose protects animals from SARS-CoV-2 infection, it also stimulates production of SARS-CoV-2 neutralizing antibodies that afford long-lasting protection from SARS-CoV-2 reinfection. Thus, eTIP1 is a safe and effective broad-spectrum antiviral generating short- and long-term protection against SARS-CoV-2 and other respiratory infections in animal models.


Asunto(s)
Proteínas de la Cápside/genética , Virus Interferentes Defectuosos/metabolismo , Replicación Viral/efectos de los fármacos , Administración Intranasal , Animales , Antivirales/farmacología , Anticuerpos ampliamente neutralizantes/inmunología , Anticuerpos ampliamente neutralizantes/farmacología , COVID-19 , Proteínas de la Cápside/metabolismo , Línea Celular , Virus Interferentes Defectuosos/patogenicidad , Modelos Animales de Enfermedad , Genoma Viral/genética , Humanos , Gripe Humana , Interferones/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Poliovirus/genética , Poliovirus/metabolismo , Infecciones del Sistema Respiratorio/virología , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/patogenicidad
3.
Genes Dev ; 35(17-18): 1243-1255, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34385262

RESUMEN

Multiple G protein-coupled receptors (GPCRs) are expressed in pancreatic islet cells, but the majority have unknown functions. We observed specific GPCRs localized to primary cilia, a prominent signaling organelle, in pancreatic α and ß cells. Loss of cilia disrupts ß-cell endocrine function, but the molecular drivers are unknown. Using functional expression, we identified multiple GPCRs localized to cilia in mouse and human islet α and ß cells, including FFAR4, PTGER4, ADRB2, KISS1R, and P2RY14. Free fatty acid receptor 4 (FFAR4) and prostaglandin E receptor 4 (PTGER4) agonists stimulate ciliary cAMP signaling and promote glucagon and insulin secretion by α- and ß-cell lines and by mouse and human islets. Transport of GPCRs to primary cilia requires TULP3, whose knockdown in primary human and mouse islets relocalized ciliary FFAR4 and PTGER4 and impaired regulated glucagon or insulin secretion, without affecting ciliary structure. Our findings provide index evidence that regulated hormone secretion by islet α and ß cells is controlled by ciliary GPCRs providing new targets for diabetes.


Asunto(s)
Células Secretoras de Insulina , Islotes Pancreáticos , Animales , Glucagón/metabolismo , Insulina/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Receptores Acoplados a Proteínas G/genética
4.
Small ; 20(43): e2401929, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38934508

RESUMEN

Defective bismuth telluride (Bi2Te3) nanosheets, an artificial nanozyme mimicking haloperoxidase activity (hPOD), show promise as eco-friendly, bactericidal, and antimicrofouling materials by enhancing cytotoxic hypohalous acid production from halides and H2O2. Microscopic and spectroscopic characterization reveals that controlled NaOH (upto X = 250 µL) etching of the nearly inactive non-transition metal chalcogenide Bi2Te3 nanosheets creates controlled defects (d), such as Bi3+species, in d-Bi2Te3-X that induces enhanced hPOD activity. d-Bi2Te3-250 exhibits approximately eight-fold improved hPOD than the as-grown Bi2Te3 nanosheets. The antibacterial activity of d-Bi2Te3-250 nanozymes, studied by bacterial viability, show 1, and 45% viability for Staphylococcus aureus and Pseudomonas aeruginosa, respectively, prevalent in marine environments. The hPOD mechanism is confirmed using scavengers, implicating HOBr and singlet oxygen for the effect. The antimicrofouling property of the d-Bi2Te3-250 nanozyme has been studied on Pseudomonas aeruginosa biofilm in a lab setting by multiple assays, and also on titanium (Ti) plates coated with the nanozyme mixed commercial paint, exposed to seawater in a real setting. All studies, including direct microscopic evidence, exhibit inhibition of microfouling, up to ≈73%, in the presence of nanozymes. This approach showcases that defect engineering can induce antibacterial, and antimicrofouling activity in non-transition metal chalcogenides, offering an inexpensive alternative to noble metals.


Asunto(s)
Bismuto , Nanoestructuras , Pseudomonas aeruginosa , Telurio , Bismuto/química , Bismuto/farmacología , Telurio/química , Nanoestructuras/química , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Incrustaciones Biológicas/prevención & control , Antibacterianos/farmacología , Antibacterianos/química , Peroxidasas/metabolismo , Pruebas de Sensibilidad Microbiana
5.
PLoS Pathog ; 17(9): e1009898, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34478458

RESUMEN

The respiratory disease COVID-19 is caused by the coronavirus SARS-CoV-2. Here we report the discovery of ethacridine as a potent drug against SARS-CoV-2 (EC50 ~ 0.08 µM). Ethacridine was identified via high-throughput screening of an FDA-approved drug library in living cells using a fluorescence assay. Plaque assays, RT-PCR and immunofluorescence imaging at various stages of viral infection demonstrate that the main mode of action of ethacridine is through inactivation of viral particles, preventing their binding to the host cells. Consistently, ethacridine is effective in various cell types, including primary human nasal epithelial cells that are cultured in an air-liquid interface. Taken together, our work identifies a promising, potent, and new use of the old drug via a distinct mode of action for inhibiting SARS-CoV-2.


Asunto(s)
Antivirales/farmacología , Etacridina/farmacología , Inhibidores de Proteasas/farmacología , Activación Viral/efectos de los fármacos , Animales , Línea Celular , Chlorocebus aethiops , Proteasas 3C de Coronavirus/antagonistas & inhibidores , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Humanos , Células Vero , Virión/efectos de los fármacos , Replicación Viral/efectos de los fármacos
6.
Child Psychiatry Hum Dev ; 49(6): 993-1002, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29872997

RESUMEN

This two stage study examined the effects of acute exercise on resting electroencephalographic (EEG) patterns of children with attention-deficit hyperactivity disorder (ADHD). The first stage compared the neural oscillatory patterns of children with and without ADHD. Resting EEGs were recorded under an open-eyes condition from 24 boys with ADHD and 28 matched controls. The second stage of the study employed a randomized cross-over trial design. The 24 boys with ADHD engaged in a 30-min intervention that consisted of either running on a treadmill or watching a video on alternative days, with resting EEGs recorded before and after treatment. The first stage found that children with ADHD exhibited significantly higher theta/beta ratios over the midline electrodes sites than controls. The second stage further indicated that children with ADHD displayed smaller theta/beta ratios following the exercise condition compared with the video-watching condition. This finding suggests that acute exercise normalizes arousal and alertness of children with ADHD, as reflected in resting EEG readings.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Encéfalo/fisiopatología , Ejercicio Físico/fisiología , Adolescente , Nivel de Alerta/fisiología , Estudios de Casos y Controles , Niño , Estudios Cruzados , Electroencefalografía , Humanos , Masculino
7.
EMBO J ; 32(8): 1141-54, 2013 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-23511974

RESUMEN

Centrioles are cylindrical structures that are usually composed of nine triplets of microtubules (MTs) organized around a cartwheel-shaped structure. Recent studies have proposed a structural model of the SAS-6-based cartwheel, yet we do not know the molecular detail of how the cartwheel participates in centriolar MT assembly. In this study, we demonstrate that the human microcephaly protein, CEP135, directly interacts with hSAS-6 via its carboxyl-terminus and with MTs via its amino-terminus. Unexpectedly, CEP135 also interacts with another microcephaly protein CPAP via its amino terminal domain. Depletion of CEP135 not only perturbed the centriolar localization of CPAP, but also blocked CPAP-induced centriole elongation. Furthermore, CEP135 depletion led to abnormal centriole structures with altered numbers of MT triplets and shorter centrioles. Overexpression of a CEP135 mutant lacking the proper interaction with hSAS-6 had a dominant-negative effect on centriole assembly. We propose that CEP135 may serve as a linker protein that directly connects the central hub protein, hSAS-6, to the outer MTs, and suggest that this interaction stabilizes the proper cartwheel structure for further CPAP-mediated centriole elongation.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular/metabolismo , Centriolos/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Línea Celular , Centriolos/ultraestructura , Humanos , Modelos Biológicos , Unión Proteica , Mapeo de Interacción de Proteínas
8.
EMBO J ; 30(23): 4790-804, 2011 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-22020124

RESUMEN

Centriole duplication involves the growth of a procentriole next to the parental centriole. Mutations in STIL and CPAP/CENPJ cause primary microcephaly (MCPH). Here, we show that human STIL has an asymmetric localization to the daughter centriole and is required for procentriole formation. STIL levels oscillate during the cell cycle. Interestingly, STIL interacts directly with CPAP and forms a complex with hSAS6. A natural mutation of CPAP (E1235V) that causes MCPH in humans leads to significantly lower binding to STIL. Overexpression of STIL induced the formation of multiple procentrioles around the parental centriole. STIL depletion inhibited normal centriole duplication, Plk4-induced centriole amplification, and CPAP-induced centriole elongation, and resulted in a failure to localize hSAS6 and CPAP to the base of the nascent procentriole. Furthermore, hSAS6 depletion hindered STIL targeting to the procentriole, implying that STIL and hSAS6 are mutually dependent for their centriolar localization. Together, our results indicate that the two MCPH-associated proteins STIL and CPAP interact with each other and are required for procentriole formation, implying a central role of centriole biogenesis in MCPH.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Centriolos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Microcefalia/fisiopatología , Proteínas Asociadas a Microtúbulos/metabolismo , Animales , Bovinos , Ciclo Celular/fisiología , División Celular/fisiología , Células Cultivadas , Centriolos/genética , Centriolos/metabolismo , Centriolos/patología , Células HEK293 , Células HeLa , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Microcefalia/genética , Microscopía Confocal , Microscopía Fluorescente , Proteínas Asociadas a Microtúbulos/genética , Unión Proteica
9.
JACS Au ; 4(10): 3976-3987, 2024 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-39483239

RESUMEN

Phosphinopyridyl ligands are used to synthesize a class of Ni(II) bis(chelate) complexes, which have been comprehensively characterized in both solid and solution phases. The structures display a square-planar configuration within the primary coordination sphere, with axially positioned labile binding sites. Their electrochemical data reveal two redox couples during the reduction process, suggesting the possibility of accessing two-electron reduction states. Significantly, these complexes serve as robust catalysts for homogeneous photocatalytic H2 evolution. In a system utilizing an organic photosensitizer and a sacrificial electron donor, an optimal turnover number of 27,100 is achieved in an alcohol-containing aqueous solution. A series of photophysical and electrochemical measurements were conducted to elucidate the reaction mechanism of photocatalytic hydrogen generation. Density function theory calculations propose a catalytic pathway involving two successive one-electron reduction steps, followed by two proton discharges. The sustained photocatalytic activity of these complexes stems from their distinct ligand system, which includes phosphine and pyridine donors that aid in stabilizing the low oxidation states of the Ni center.

10.
Brain Cogn ; 82(1): 43-57, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23511845

RESUMEN

This study examined behavioral and neuroelectric intra-individual variability (IIV) in preadolescent children during a task requiring variable amounts of cognitive control. The current study further examined whether IIV was moderated by aerobic fitness level. Participants performed a modified flanker task, comprised of congruent and incongruent arrays, within compatible and incompatible stimulus-response conditions. Results revealed that congruent, relative to incongruent, conditions were associated with less IIV of RT. Further, less IIV of RT, P3 amplitude, and P3 latency was observed for the compatible relative to the incompatible condition. Higher fitness was associated with shorter and less variable RT only for the incompatible condition, with no fitness-related differences observed for P3 variability. The findings suggest that conditions requiring greater cognitive control are associated with increased IIV, and that higher fitness may be associated with greater integrity of cognitive control systems during development.


Asunto(s)
Encéfalo/fisiología , Cognición/fisiología , Potenciales Evocados/fisiología , Individualidad , Inteligencia/fisiología , Aptitud Física/fisiología , Niño , Electroencefalografía , Ejercicio Físico/fisiología , Ejercicio Físico/psicología , Femenino , Humanos , Masculino , Ventilación Voluntaria Máxima/fisiología , Pruebas Neuropsicológicas , Consumo de Oxígeno/fisiología , Aptitud Física/psicología , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología
11.
Nanoscale ; 15(6): 2586-2594, 2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36691938

RESUMEN

Since quantum computers have been gradually introduced in countries around the world, the development of the many related quantum components that can operate independently of temperature has become more important for enabling mature products with low power dissipation and high efficiency. As an alternative to studying cryo-CMOSs (complementary metal-oxide-semiconductors) to achieve this goal, quantum tunneling devices based on 2D materials can be examined instead. In this work, a vertical graphene-based quantum tunneling transistor has been used as a frequency modulator. The transistor can operate via different quantum tunneling mechanisms and generates, by applying the appropriate bias, voltage-resistance curves characteristic of variable nonlinear resistance for both base and emitter voltages. We experimentally demonstrate frequency modulation from input signals over the range of 100 kHz to 10 MHz, enabling a tunable frequency doubler or tripler in just a single transistor. This frequency multiplication with a tunneling mechanism makes the graphene-based tunneling device a promising option for frequency electronics in the emerging field of quantum technologies.

12.
Nat Microbiol ; 8(1): 121-134, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36604514

RESUMEN

The coronavirus SARS-CoV-2 causes the severe disease COVID-19. SARS-CoV-2 infection is initiated by interaction of the viral spike protein and host receptor angiotensin-converting enzyme 2 (ACE2). We report an improved bright and reversible fluorogenic reporter, named SURF (split UnaG-based reversible and fluorogenic protein-protein interaction reporter), that we apply to monitor real-time interactions between spike and ACE2 in living cells. SURF has a large dynamic range with a dark-to-bright fluorescence signal that requires no exogenous cofactors. Utilizing this reporter, we carried out a high-throughput screening of small-molecule libraries. We identified three natural compounds that block replication of SARS-CoV-2 in both Vero cells and human primary nasal and bronchial epithelial cells. Cell biological and biochemical experiments validated all three compounds and showed that they block the early stages of viral infection. Two of the inhibitors, bruceine A and gamabufotalin, were also found to block replication of the Delta and Omicron variants of SARS-CoV-2. Both bruceine A and gamabufotalin exhibited potent antiviral activity in K18-hACE2 and wild-type C57BL6/J mice, as evidenced by reduced viral titres in the lung and brain, and protection from alveolar and peribronchial inflammation in the lung, thereby limiting disease progression. We propose that our fluorescent assay can be applied to identify antiviral compounds with potential as therapeutic treatment for COVID-19 and other respiratory diseases.


Asunto(s)
COVID-19 , SARS-CoV-2 , Chlorocebus aethiops , Ratones , Humanos , Animales , SARS-CoV-2/metabolismo , Células Vero , Enzima Convertidora de Angiotensina 2 , Peptidil-Dipeptidasa A/metabolismo , Antivirales/farmacología
13.
J Int Soc Sports Nutr ; 19(1): 316-335, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35813850

RESUMEN

Background: CrossFit® is a popular high-intensity functional training program. CrossFit® participants may practice popular diets or consume dietary and sports supplements to support their health or physical pursuits, but the specific dietary and supplement practices of CrossFit® participants remain unknown. Methods: An electronic questionnaire was developed to collect data on practice of popular diets (i.e. Paleo and The Zone Diet®), dietary and sports supplement use, reasons for practicing a diet or using supplements, sources of information on diets and supplements, and various beliefs associated with nutrition among CrossFit® participants. Results: Of the 2,576 complete responses (female 51.9%, male 48.1%, age 39.4 ± 11.1 years, body mass index 26.1 ± 3.9 kg/m2), 695 (27%) reported being a CrossFit® trainer or coach and 1,392 (54%) reported competing, or planning to compete, in CrossFit® or other fitness competitions. The average years of CrossFit® experience were 5.3 ± 3.1 years, and the average frequency of CrossFit® participation was 4.5 ± 1.1 days/week. Most participants (60.1%) reported practicing a particular diet. Macro Counting (18.6%), Intermittent Fasting (7.7%), and Paleo (6.1%) were the most frequently reported diets. The top reasons for practicing a diet were to improve overall health (45.6%), decrease body fat (29.2%), and improve CrossFit® performance (25.2%). The top sources of dietary information were the Internet (47.5%), coach/trainer (28.7%), and nutritionist/dietitian (26.2%). Most participants (67.3%) reported "Urine Color" as the best method to assess hydration. Additionally, most participants (82.2%) consumed at least one supplement, with protein (51.2%), creatine (22.9%), and pre-workout/energy (20.7%) being most popular. The top reasons for consuming supplements were to improve recovery (52.6%), improve overall health (51.4%), and increase muscle mass/strength (41.7%). The top sources of information on supplements were the Internet (53.1%), coach/trainer (27.0%), and peer-reviewed research (23.0%). Conclusions: A large proportion of CrossFit® participants may practice popular diets or consume supplements with the intention of improving health or performance. These findings may support future research on the effects of various dietary patterns and supplements on CrossFit® performance.


Asunto(s)
Suplementos Dietéticos , Deportes , Adulto , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
14.
ACS Nano ; 16(2): 2369-2380, 2022 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-35099945

RESUMEN

To realize the quantum anomalous Hall effect (QAHE) at elevated temperatures, the approach of magnetic proximity effect (MPE) was adopted to break the time-reversal symmetry in the topological insulator (Bi0.3Sb0.7)2Te3 (BST) based heterostructures with a ferrimagnetic insulator europium iron garnet (EuIG) of perpendicular magnetic anisotropy. Here we demonstrate large anomalous Hall resistance (RAHE) exceeding 8 Ω (ρAHE of 3.2 µΩ·cm) at 300 K and sustaining to 400 K in 35 BST/EuIG samples, surpassing the past record of 0.28 Ω (ρAHE of 0.14 µΩ·cm) at 300 K. The large RAHE is attributed to an atomically abrupt, Fe-rich interface between BST and EuIG. Importantly, the gate dependence of the AHE loops shows no sign change with varying chemical potential. This observation is supported by our first-principles calculations via applying a gradient Zeeman field plus a contact potential on BST. Our calculations further demonstrate that the AHE in this heterostructure is attributed to the intrinsic Berry curvature. Furthermore, for gate-biased 4 nm BST on EuIG, a pronounced topological Hall effect-like (THE-like) feature coexisting with AHE is observed at the negative top-gate voltage up to 15 K. Interface tuning with theoretical calculations has realized topologically distinct phenomena in tailored magnetic TI-based heterostructures.

15.
Carcinogenesis ; 32(12): 1890-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21983128

RESUMEN

Ling Zhi-8 (LZ-8), an immunomodulatory protein, is derived from and has been cloned from the medicinal mushroom Ganoderma lucidum (Reishi or Ling Zhi); this protein exhibits immunomodulating and antitumor properties. We investigated the effects of recombinant LZ-8 protein (rLZ-8) on the proliferation of A549 human lung cancer cells. Here, we showed that rLZ-8 inhibits cell growth and that this is correlated with increased G(1) arrest. The treatment of A549 cells with rLZ-8 activated p53 and p21 expression, and both the G(1) arrest and the antigrowth effect were found to be p53 dependent. It was further demonstrated that rLZ-8 inhibited tumor growth in mice transplanted with Lewis lung carcinoma cells. Interestingly, rLZ-8 treatment was found to lead to nucleolar stress (or ribosomal stress) as evidenced by inhibition of precursor ribosomal RNA synthesis and reduced polysome formation in A549 cells. These changes resulted in an increasing binding of ribosomal protein S7 to MDM2 and a decreased interaction between MDM2 and p53. Taking these results together, we have identified a novel rLZ-8 antitumor function that positively modulates p53 via ribosomal stress and inhibits lung cancer cell growth in vitro and in vivo. Our current results suggest that rLZ-8 may have potential as a therapeutic intervention for the treatment of cancers that contain wild-type p53 and high expression of MDM2.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Proteínas Fúngicas/farmacología , Neoplasias Pulmonares/patología , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Ribosómicas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Secuencia de Bases , Cartilla de ADN , Humanos , Neoplasias Pulmonares/metabolismo , Ratones , Trasplante de Neoplasias , Interferencia de ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas
16.
Dev Sci ; 14(5): 1046-58, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21884320

RESUMEN

The present study examined the effects of a 9-month randomized control physical activity intervention aimed at improving cardiorespiratory fitness on changes in working memory performance in preadolescent children relative to a waitlist control group. Participants performed a modified Sternberg task, which manipulated working memory demands based on encoding set sizes, while task performance and the contingent negative variation (CNV) event-related brain potential were measured. Analyses revealed that the physical activity intervention led to increases in cardiorespiratory fitness and improved Sternberg task performance. Further, the beneficial effects of the physical activity intervention were greater for a task condition requiring greater working memory demands. In addition, the intervention group exhibited larger initial CNV at the frontal electrode site, relative to the waitlist group at post-test; an effect not observed during the pre-test. These results indicate that increases in cardiorespiratory fitness are associated with improvements in the cognitive control of working memory in preadolescent children.


Asunto(s)
Memoria a Corto Plazo , Actividad Motora , Aptitud Física , Niño , Variación Contingente Negativa , Potenciales Evocados , Femenino , Humanos , Aprendizaje , Masculino , Instituciones Académicas , Análisis y Desempeño de Tareas
17.
Cell Metab ; 33(8): 1565-1576.e5, 2021 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-34081912

RESUMEN

Emerging evidence points toward an intricate relationship between the pandemic of coronavirus disease 2019 (COVID-19) and diabetes. While preexisting diabetes is associated with severe COVID-19, it is unclear whether COVID-19 severity is a cause or consequence of diabetes. To mechanistically link COVID-19 to diabetes, we tested whether insulin-producing pancreatic ß cells can be infected by SARS-CoV-2 and cause ß cell depletion. We found that the SARS-CoV-2 receptor, ACE2, and related entry factors (TMPRSS2, NRP1, and TRFC) are expressed in ß cells, with selectively high expression of NRP1. We discovered that SARS-CoV-2 infects human pancreatic ß cells in patients who succumbed to COVID-19 and selectively infects human islet ß cells in vitro. We demonstrated that SARS-CoV-2 infection attenuates pancreatic insulin levels and secretion and induces ß cell apoptosis, each rescued by NRP1 inhibition. Phosphoproteomic pathway analysis of infected islets indicates apoptotic ß cell signaling, similar to that observed in type 1 diabetes (T1D). In summary, our study shows SARS-CoV-2 can directly induce ß cell killing.


Asunto(s)
COVID-19/virología , Diabetes Mellitus/virología , Células Secretoras de Insulina/virología , Neuropilina-1/metabolismo , Receptores Virales/metabolismo , SARS-CoV-2/patogenicidad , Internalización del Virus , Células A549 , Adulto , Anciano , Anciano de 80 o más Años , Enzima Convertidora de Angiotensina 2/metabolismo , Antígenos CD/metabolismo , Apoptosis , Proteínas Reguladoras de la Apoptosis/metabolismo , COVID-19/complicaciones , COVID-19/diagnóstico , Estudios de Casos y Controles , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/metabolismo , Femenino , Interacciones Huésped-Patógeno , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Persona de Mediana Edad , Receptores de Transferrina/metabolismo , SARS-CoV-2/metabolismo , Serina Endopeptidasas/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismo
18.
Cell Rep Med ; 2(10): 100421, 2021 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-34604819

RESUMEN

Understanding viral tropism is an essential step toward reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, decreasing mortality from coronavirus disease 2019 (COVID-19) and limiting opportunities for mutant strains to arise. Currently, little is known about the extent to which distinct tissue sites in the human head and neck region and proximal respiratory tract selectively permit SARS-CoV-2 infection and replication. In this translational study, we discover key variabilities in expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), essential SARS-CoV-2 entry factors, among the mucosal tissues of the human proximal airways. We show that SARS-CoV-2 infection is present in all examined head and neck tissues, with a notable tropism for the nasal cavity and tracheal mucosa. Finally, we uncover an association between smoking and higher SARS-CoV-2 viral infection in the human proximal airway, which may explain the increased susceptibility of smokers to developing severe COVID-19. This is at least partially explained by differences in interferon (IFN)-ß1 levels between smokers and non-smokers.


Asunto(s)
Enzima Convertidora de Angiotensina 2/genética , COVID-19/transmisión , Mucosa Respiratoria/metabolismo , Serina Endopeptidasas/genética , Fumadores , Tropismo Viral , Anciano , Anciano de 80 o más Años , COVID-19/genética , COVID-19/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Cavidad Nasal/metabolismo , SARS-CoV-2/fisiología , Tráquea/metabolismo
19.
Healthcare (Basel) ; 8(2)2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32260259

RESUMEN

Rheumatoid arthritis (RA) is a systematic chronic inflammatory disease. The disease mechanism remains unclear and may have resulted from autoimmune problems caused by genetic predisposing and pathogen infection. In clinical practice, selection of the initial treatment is based on the degree of disease activity, and treatment plans will be added gradually according to increased severity of the disease. However, treatment results can be unclear and treatment process uncertain and ambiguous, which can cause healthcare quality to become worse. This study attempts to combine expert opinions to construct various classifiers using a number of data mining techniques to analyze the different prognosis of two patient groups, by predicting whether the inflammatory indicator erythrocyte sedimentation rates of these two groups will be within the normal range with different medication strategies. Clinical data were collected for construction of different classifiers and we evaluate the prediction accuracy rate of each classifier afterwards. The optimum prediction model is selected from these classifiers to predict the prognosis of RA within these treatment strategies and analyze various results. The results show the accuracy rate of the prediction model by Logistic, SVM and DT module were 0.7927, 07829 and 0.9094, respectively. In the RA complications dataset, the accuracy rate of were 0.9393, 0.9290 and 0.9812, respectively. Futhermore, gain ratio was used to further analyze the rules and to discover which branch nodes are the most importance factor. The results of this study are helpful for formulation and development of guidelines for clinical RA treatments, and implementation of a decision support system by using the prediction model can assist medical staff to make correct decisions in the disease's early stage.

20.
Nanomaterials (Basel) ; 10(8)2020 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-32748811

RESUMEN

The role of an atomic-layer thick periodic Y-O array in inducing the epitaxial growth of single-crystal hexagonal YAlO3 perovskite (H-YAP) films was studied using high-angle annular dark-field and annular bright-field scanning transmission electron microscopy in conjunction with a spherical aberration-corrected probe and in situ reflection high-energy electron diffraction. We observed the Y-O array at the interface of amorphous atomic layer deposition (ALD) sub-nano-laminated (snl) Al2O3/Y2O3 multilayers and GaAs(111)A, with the first film deposition being three cycles of ALD-Y2O3. This thin array was a seed layer for growing the H-YAP from the ALD snl multilayers with 900 °C rapid thermal annealing (RTA). The annealed film only contained H-YAP with an excellent crystallinity and an atomically sharp interface with the substrate. The initial Y-O array became the bottom layer of H-YAP, bonding with Ga, the top layer of GaAs. Using a similar ALD snl multilayer, but with the first film deposition of three ALD-Al2O3 cycles, there was no observation of a periodic atomic array at the interface. RTA of the sample to 900 °C resulted in a non-uniform film, mixing amorphous regions and island-like H-YAP domains. The results indicate that the epitaxial H-YAP was induced from the atomic-layer thick periodic Y-O array, rather than from GaAs(111)A.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA