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1.
J Infect Dis ; 223(1): 101-108, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-32561934

RESUMEN

It has been demonstrated that activated mast cells (MCs) are enriched in Kaposi sarcoma (KS) tumors and contribute to the inflammatory microenvironment. Mechanisms driving MC activation, however, are incompletely understood. We sought to understand whether immunoglobulin E (IgE), a potent activator of MCs, was associated with KS incidence and severity. In a cross-sectional study of untreated human immunodeficiency virus (HIV)-infected adults with or without KS in Uganda, we found that patients with KS had higher plasma IgE levels than those without KS. After adjustment for age, sex, CD4+ T-cell count, and HIV RNA levels, there was a dose-response relationship between plasma IgE levels and the presence and severity of KS. Higher eosinophil counts were also associated with IgE levels, and plasma interleukin 33 concentrations were higher in individuals with KS. These findings suggest that IgE-driven atopic inflammation may contribute the pathogenesis of KS. Therapies targeting IgE-mediated MC activation thus might represent a novel approach for treatment or prevention of KS.


Asunto(s)
Infecciones por VIH/virología , Inmunoglobulina E/sangre , Sarcoma de Kaposi/virología , Adulto , Recuento de Linfocito CD4 , Estudios de Casos y Controles , Estudios Transversales , Femenino , Infecciones por VIH/complicaciones , Humanos , Interleucina-33/sangre , Masculino , Sarcoma de Kaposi/sangre , Sarcoma de Kaposi/etiología , Índice de Severidad de la Enfermedad , Uganda
2.
J Gen Virol ; 101(5): 484-496, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32141809

RESUMEN

Dengue virus (DENV) causes an estimated 390 million infections worldwide annually, with severe forms of disease marked by vascular leakage. Endothelial cells (EC) are directly responsible for vascular homeostasis and are highly responsive to circulating mediators but are not commonly infected. DENV encodes seven non-structural (NS) proteins; with only one of those, NS1, secreted from infected cells and accumulating in the blood of patients. NS1 has been implicated in the pathogenesis of vascular permeability, but the mechanism is not completely understood. Here we used primary endothelial cells and an array of in vitro approaches to study the effect of NS1 in disease-relevant human ECs. Confocal microscopy demonstrated rapid NS1 internalization by ECs into endosomes with accumulation over time. Transcriptomic and pathway analysis showed significant changes in functions associated with EC homeostasis and vascular permeability. Functional significance of this activation was assessed by trans-endothelial electrical resistance and showed that NS1 induced rapid and transient loss in EC barrier function within 3 h post-treatment. To understand the molecular mechanism by which NS1 induced EC activation, we evaluated the stress-sensing p38 MAPK pathway known to be directly involved in EC permeability and inflammation. WB analysis of NS1-stimulated ECs showed clear activation of p38 MAPK and downstream effectors MAPKAPK-2 and HSP27 with chemical inhibition of the p38 MAP kinase pathway restoring barrier function. Our results suggest that DENV NS1 may be involved in the pathogenesis of severe dengue by activating the p38 MAPK in ECs, promoting increased permeability that characterizes severe disease.


Asunto(s)
Permeabilidad Capilar/fisiología , Virus del Dengue/metabolismo , Dengue/metabolismo , Células Endoteliales/metabolismo , Células Endoteliales/virología , Proteínas no Estructurales Virales/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Línea Celular , Dengue/virología , Endotelio Vascular/metabolismo , Endotelio Vascular/virología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Transducción de Señal/fisiología
3.
Emerg Med J ; 37(10): 650-651, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32978249

RESUMEN

A short-cut review of the available medical literature was carried out to establish whether esmolol was an effective treatment for patients in cardiac arrest. After abstract review, two papers were found to answer this clinical question using the detailed search strategy. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that there is insufficient research addressing this question to know whether esmolol is a potential treatment for cardiac arrest.


Asunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Apoyo Vital Cardíaco Avanzado , Paro Cardíaco/tratamiento farmacológico , Propanolaminas/uso terapéutico , Medicina de Emergencia Basada en la Evidencia , Paro Cardíaco/mortalidad , Humanos
4.
Am J Kidney Dis ; 74(6): 727-735, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31540789

RESUMEN

RATIONALE & OBJECTIVE: Clinical practice guidelines recommend delivering a continuous renal replacement therapy (CRRT) dose of 20 to 25mL/kg/h. However, practice patterns nationwide are highly variable; this inconsistent prescribing may lead to errors in medication dosing and increase rates of electrolyte and acid-base abnormalities. We describe an initiative to standardize CRRT practice patterns and reduce dosing variability. STUDY DESIGN: Quality improvement study. SETTING & PARTICIPANTS: Adult patients treated with CRRT at the University of Colorado Hospital between January 2016 and October 2017. QUALITY IMPROVEMENT ACTIVITIES: An assessment of the magnitude of the variability in CRRT dosing and the following specific interventions were implemented during the course of 1 year: (1) modification of the electronic medical record (EMR) to include calculated average 24-hour dose in real time, (2) modification of the CRRT procedure note to include comments on dosing, (3) modification of the CRRT order set to display calculations, and (4) yearly educational sessions for renal fellows outlining CRRT-specific dosing targets. OUTCOMES: The primary outcome was weekly percentage of CRRT treatments with an average delivered daily dose of 20 to 25mL/kg/h. Process and balancing outcomes included CRRT flowsheet accuracy, documentation of rates of delivered dose, and nursing satisfaction. ANALYTICAL APPROACH: Rates of weekly CRRT dosing in compliance with national guidelines were determined and used to create run charts showing compliance rates before and after the quality improvement interventions. RESULTS: Among 837 treatments before the intervention, 279 (33%) daily CRRT sessions achieved an average dose of 20 to 25mL/kg/h. Following implementation of interventions, 631 of 952 (66%) treatments achieved this goal. Week-to-week variation in dosing was significantly reduced. LIMITATIONS: A single-center study generating data that may not be generalizable to institutions with different CRRT nursing models or different EMR systems. CONCLUSIONS: Changes to the EMR and documentation templates and education of CRRT providers about dosing were associated with doubling of the rate of appropriate CRRT dosing and reduction in dosing variability.


Asunto(s)
Lesión Renal Aguda/mortalidad , Lesión Renal Aguda/terapia , Terapia de Reemplazo Renal Continuo/métodos , Soluciones para Diálisis/administración & dosificación , Mejoramiento de la Calidad , Lesión Renal Aguda/diagnóstico , Adulto , Anciano , Colorado , Terapia de Reemplazo Renal Continuo/mortalidad , Enfermedad Crítica/mortalidad , Enfermedad Crítica/terapia , Esquema de Medicación , Femenino , Mortalidad Hospitalaria , Hospitales Universitarios , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Medición de Riesgo
5.
Nature ; 477(7365): 457-61, 2011 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-21881561

RESUMEN

The discovery of antibiotics more than 70 years ago initiated a period of drug innovation and implementation in human and animal health and agriculture. These discoveries were tempered in all cases by the emergence of resistant microbes. This history has been interpreted to mean that antibiotic resistance in pathogenic bacteria is a modern phenomenon; this view is reinforced by the fact that collections of microbes that predate the antibiotic era are highly susceptible to antibiotics. Here we report targeted metagenomic analyses of rigorously authenticated ancient DNA from 30,000-year-old Beringian permafrost sediments and the identification of a highly diverse collection of genes encoding resistance to ß-lactam, tetracycline and glycopeptide antibiotics. Structure and function studies on the complete vancomycin resistance element VanA confirmed its similarity to modern variants. These results show conclusively that antibiotic resistance is a natural phenomenon that predates the modern selective pressure of clinical antibiotic use.


Asunto(s)
Genes Bacterianos/genética , Metagenómica , Resistencia a la Vancomicina/genética , Animales , Antibacterianos/farmacología , Bacterias/clasificación , Bacterias/enzimología , Bacterias/genética , Teorema de Bayes , Cristalografía por Rayos X , ADN de Cloroplastos/genética , Congelación , Genes Mitocondriales/genética , Genes de Plantas/genética , Sedimentos Geológicos/microbiología , Historia Antigua , Enlace de Hidrógeno , Modelos Moleculares , Datos de Secuencia Molecular , Filogenia , Conformación Proteica , ARN Ribosómico/genética , ARN Ribosómico 16S/genética , Siberia , Resistencia a la Vancomicina/efectos de los fármacos , Vertebrados/genética , beta-Lactamasas/genética
6.
Sensors (Basel) ; 17(8)2017 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-28771168

RESUMEN

To address the need for asthma self-management in pediatrics, the authors present the feasibility of a mobile health (mHealth) platform built on their prior work in an asthmatic adult and child. Real-time asthma attack risk was assessed through physiological and environmental sensors. Data were sent to a cloud via a smartwatch application (app) using Health Insurance Portability and Accountability Act (HIPAA)-compliant cryptography and combined with online source data. A risk level (high, medium or low) was determined using a random forest classifier and then sent to the app to be visualized as animated dragon graphics for easy interpretation by children. The feasibility of the system was first tested on an adult with moderate asthma, then usability was examined on a child with mild asthma over several weeks. It was found during feasibility testing that the system is able to assess asthma risk with 80.10 ± 14.13% accuracy. During usability testing, it was able to continuously collect sensor data, and the child was able to wear, easily understand and enjoy the use of the system. If tested in more individuals, this system may lead to an effective self-management program that can reduce hospitalization in those who suffer from asthma.


Asunto(s)
Asma , Niño , Humanos , Automanejo , Telemedicina , Interfaz Usuario-Computador , Tecnología Inalámbrica
7.
J Virol ; 89(22): 11347-55, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26339061

RESUMEN

UNLABELLED: Lytic activation of Kaposi's sarcoma-associated herpesvirus (KSHV) from latency is a critical contributor to pathogenesis and progression of KSHV-mediated disease. Development of targeted treatment strategies and improvement of lytic-phase-directed oncolytic therapies, therefore, hinge on gaining a better understanding of latency-to-lytic-phase transition. A key observation in that regard, also common to other herpesviruses, is the partial permissiveness of latently infected cells to lytic-cycle-inducing agents. Here, we address the molecular basis of why only some KSHV-infected cells respond to lytic stimuli. Since cellular signal transducer and activator of transcription 3 (STAT3) is constitutively active in KSHV-associated cancers, KSHV activates STAT3, and STAT3 has been found to regulate lytic activation of Epstein-Barr virus (EBV)-infected cells, we asked if STAT3 contributes similarly to the life cycle of KSHV. We found that high levels of STAT3 correlate with the refractory state at the single-cell level under conditions of both spontaneous and induced lytic activation; importantly, STAT3 also regulates lytic susceptibility. Further, knockdown of STAT3 suppresses the cellular transcriptional corepressor Krüppel-associated box domain-associated protein 1 (KAP1; also known as TRIM28), and suppression of KAP1 activates lytic genes, including the viral lytic switch RTA, thereby linking STAT3 via KAP1 to regulation of the balance between lytic and latent cells. These findings, taken together with those from EBV-infected and, more recently, herpes simplex virus 1 (HSV-1)-infected cells, cement the contribution of host STAT3 to persistence of herpesviruses and simultaneously reveal an important lead to devise strategies to improve lytic-phase-directed therapies for herpesviruses. IMPORTANCE: Lytic activation of the cancer-causing Kaposi's sarcoma-associated herpesvirus (KSHV) is vital to its life cycle and causation of disease. Like other herpesviruses, however, a substantial fraction of latently infected cells are resistant to lytic-phase-inducing stimuli. Investigating the molecular basis for this refractory state is essential for understanding how the virus persists and how it causes disease and to guide efforts to improve treatment of KSHV-mediated diseases. We found that, like two other herpesviruses, EBV and HSV-1, KSHV exploits the cellular transcription factor STAT3 to regulate the susceptibility of latently infected cells to lytic triggers. These findings highlight a common STAT3-centered strategy used by herpesviruses to maintain persistence in their hosts while also revealing a key molecule to pursue while devising methods to improve herpesvirus lytic-phase-directed therapies.


Asunto(s)
Herpesvirus Humano 8/patogenicidad , Proteínas Represoras/metabolismo , Factor de Transcripción STAT3/fisiología , Activación Viral/genética , Línea Celular Tumoral , Regulación Viral de la Expresión Génica , Células Endoteliales de la Vena Umbilical Humana , Humanos , Piridinas/farmacología , Interferencia de ARN , ARN Interferente Pequeño , Proteínas Represoras/antagonistas & inhibidores , Factor de Transcripción STAT3/antagonistas & inhibidores , Factor de Transcripción STAT3/genética , Sarcoma de Kaposi/patología , Sarcoma de Kaposi/virología , Proteína 28 que Contiene Motivos Tripartito , Tirfostinos/farmacología , Activación Viral/fisiología , Latencia del Virus/fisiología
8.
J Virol ; 89(4): 2301-12, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25505080

RESUMEN

UNLABELLED: Epstein-Barr virus (EBV) is a well-established B-cell-tropic virus associated with various lymphoproliferative diseases of both B-cell and non-B-cell origin. EBV is associated with a number of T-cell lymphomas; however, in vitro studies utilizing prototypical EBV type 1 (EBV-1) laboratory strains have generally failed to readily infect mature T cells in culture. The difficulties in performing in vitro T-cell experiments have left questions regarding the role of EBV in the pathogenesis of EBV-positive T-cell lymphoproliferative diseases largely unresolved. We report here that the EBV type 2 (EBV-2) strain displays a unique cell tropism for T cells. In remarkable contrast to EBV-1, EBV-2 readily infects primary T cells in vitro, demonstrating a propensity for CD8(+) T cells. EBV-2 infection of purified T cells results in expression of latency genes and ultimately leads to T-cell activation, substantial proliferation, and profound alteration of cytokine expression. The pattern of cytokine production is strikingly skewed toward chemokines with roles in lymphocyte migration, demonstrating that EBV-2 has the ability to modulate normal T-cell processes. Collectively, these novel findings identify a previously unknown cell population potentially utilized by EBV-2 to establish latency and lay the foundation for further studies to elucidate the role of EBV in the pathogenesis of T-cell lymphoproliferative diseases. IMPORTANCE: The ability of EBV to infect T cells is made apparent by its association with a variety of T-cell lymphoproliferative disorders. However, studies to elucidate the pathogenic role of EBV in these diseases have been limited by the inability to conduct in vitro T-cell infection experiments. Here, we report that EBV-2 isolates, compromised in the capacity to immortalize B cells, infect CD3(+) T cells ex vivo and propose a working model of EBV-2 persistence where alteration of T-cell functions resulting from EBV-2 infection enhances the establishment of latency in B cells. If indeed EBV-2 utilizes T cells to establish a persistent infection, this could provide one mechanism for the association of EBV with T-cell lymphomas. The novel finding that EBV-2 infects T cells in culture will provide a model to understand the role EBV plays in the development of T-cell lymphomas.


Asunto(s)
Citocinas/biosíntesis , Herpesvirus Humano 4/fisiología , Activación de Linfocitos , Linfocitos T/inmunología , Linfocitos T/virología , Tropismo Viral , Latencia del Virus , Adulto , Células Cultivadas , Herpesvirus Humano 4/inmunología , Humanos
9.
J Allergy Clin Immunol ; 136(5): 1346-54.e1, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25819983

RESUMEN

BACKGROUND: Respiratory syncytial virus (RSV) causes severe respiratory tract infections, which might have a role in the development of airway hyperreactivity. Mast cells are important effector cells in allergy, with sentinel cell roles in host defense. However, the role of mast cells in response to RSV infection is unknown. OBJECTIVE: Human mast cell responses to RSV were investigated with a view to better understanding the role of mast cells in RSV-induced disease. METHODS: Human cord blood-derived mast cells and the HMC-1 mast cell line were exposed to RSV or UV-inactivated RSV. Viral gene and protein expression were evaluated by using PCR and flow cytometry. The expression of interferon-stimulated genes and selected mediators were evaluated by using quantitative PCR and ELISA. RESULTS: Human mast cells expressed multiple RSV genes after exposure to RSV, and a small percentage of mast cells supported RSV antigen protein expression. RSV induced mast cells to upregulate production of chemokines, including CCL4, CCL5, and CXCL10, as well as type I interferons, and interferon-stimulated gene expression. However, production of the granulocyte chemoattractants CXCL8 and CCL11 was not induced. Antibody blockade of the type I interferon receptor on human cord blood-derived mast cells reduced the RSV-mediated induction of CXCL10 and CCL4 but not CCL5. Leukotriene C4 production by mast cells was not enhanced by exposure to RSV. CONCLUSION: Despite low levels of infection, human mast cells produce multiple chemokines in response to RSV through mechanisms that include responses to type I interferons. Such mast cell responses might enhance effector cell recruitment during RSV-induced disease.


Asunto(s)
Quimiocina CCL4/metabolismo , Quimiocina CXCL10/metabolismo , Interferón Tipo I/metabolismo , Mastocitos/inmunología , Infecciones por Virus Sincitial Respiratorio/inmunología , Virus Sincitiales Respiratorios/inmunología , Hiperreactividad Bronquial , Línea Celular , Sangre Fetal/citología , Humanos , Mastocitos/virología , Cultivo Primario de Células
10.
Biol Lett ; 11(3)2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25808000

RESUMEN

The present erratum is in regards to our article entitled 'Ancient DNA and the tropics: a rodent's tale'. We were made aware of problems with some of the ancient sequences submitted to GenBank and conducted a systematic review of all the files used in our study. We discovered that, unfortunately, an incorrect file was sent to GenBank and was also used in some of our downstream analyses. We immediately contacted GenBank, explained the situation and corrected the file. We have redone some analyses with the correct file and describe these changes below.

11.
J Neuroeng Rehabil ; 12: 80, 2015 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-26400061

RESUMEN

BACKGROUND: Direct brain control of overground walking in those with paraplegia due to spinal cord injury (SCI) has not been achieved. Invasive brain-computer interfaces (BCIs) may provide a permanent solution to this problem by directly linking the brain to lower extremity prostheses. To justify the pursuit of such invasive systems, the feasibility of BCI controlled overground walking should first be established in a noninvasive manner. To accomplish this goal, we developed an electroencephalogram (EEG)-based BCI to control a functional electrical stimulation (FES) system for overground walking and assessed its performance in an individual with paraplegia due to SCI. METHODS: An individual with SCI (T6 AIS B) was recruited for the study and was trained to operate an EEG-based BCI system using an attempted walking/idling control strategy. He also underwent muscle reconditioning to facilitate standing and overground walking with a commercial FES system. Subsequently, the BCI and FES systems were integrated and the participant engaged in several real-time walking tests using the BCI-FES system. This was done in both a suspended, off-the-ground condition, and an overground walking condition. BCI states, gyroscope, laser distance meter, and video recording data were used to assess the BCI performance. RESULTS: During the course of 19 weeks, the participant performed 30 real-time, BCI-FES controlled overground walking tests, and demonstrated the ability to purposefully operate the BCI-FES system by following verbal cues. Based on the comparison between the ground truth and decoded BCI states, he achieved information transfer rates >3 bit/s and correlations >0.9. No adverse events directly related to the study were observed. CONCLUSION: This proof-of-concept study demonstrates for the first time that restoring brain-controlled overground walking after paraplegia due to SCI is feasible. Further studies are warranted to establish the generalizability of these results in a population of individuals with paraplegia due to SCI. If this noninvasive system is successfully tested in population studies, the pursuit of permanent, invasive BCI walking prostheses may be justified. In addition, a simplified version of the current system may be explored as a noninvasive neurorehabilitative therapy in those with incomplete motor SCI.


Asunto(s)
Interfaces Cerebro-Computador , Terapia por Estimulación Eléctrica/instrumentación , Terapia por Estimulación Eléctrica/métodos , Paraplejía/rehabilitación , Traumatismos de la Médula Espinal/rehabilitación , Encéfalo/fisiopatología , Electroencefalografía/métodos , Estudios de Factibilidad , Humanos , Masculino , Paraplejía/etiología , Prótesis e Implantes , Traumatismos de la Médula Espinal/complicaciones , Caminata/fisiología
12.
J Neuroeng Rehabil ; 12: 57, 2015 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-26162751

RESUMEN

BACKGROUND: Many stroke survivors have significant long-term gait impairment, often involving foot drop. Current physiotherapies provide limited recovery. Orthoses substitute for ankle strength, but they provide no lasting therapeutic effect. Brain-computer interface (BCI)-controlled functional electrical stimulation (FES) is a novel rehabilitative approach that may generate permanent neurological improvements. This study explores the safety and feasibility of a foot-drop-targeted BCI-FES physiotherapy in chronic stroke survivors. METHODS: Subjects (n = 9) operated an electroencephalogram-based BCI-FES system for foot dorsiflexion in 12 one-hour sessions over four weeks. Gait speed, dorsiflexion active range of motion (AROM), six-minute walk distance (6MWD), and Fugl-Meyer leg motor (FM-LM) scores were assessed before, during, and after therapy. The primary safety outcome measure was the proportion of subjects that deteriorated in gait speed by ≥0.16 m/s at one week or four weeks post-therapy. The secondary outcome measures were the proportion of subjects that experienced a clinically relevant decrease in dorsiflexion AROM (≥2.5°), 6MWD (≥20 %), and FM-LM score (≥10 %) at either post-therapy assessment. RESULTS: No subjects (0/9) experienced a clinically significant deterioration in gait speed, dorsiflexion AROM, 6MWT distance, or FM-LM score at either post-therapy assessment. Five subjects demonstrated a detectable increase (≥0.06 m/s) in gait speed, three subjects demonstrated a detectable increase (≥2.5°) in dorsiflexion AROM, five subjects demonstrated a detectable increase (≥10 %) in 6MWD, and three subjects demonstrated a detectable increase (≥10 %) in FM-LM. Five of the six subjects that exhibited a detectable increase in either post-therapy gait speed or 6MWD also exhibited significant (p < 0.01 using a Mann-Whitney U test) increases in electroencephalogram event-related synchronization/desynchronization. Additionally, two subjects experienced a clinically important increase (≥0.16 m/s) in gait speed, and four subjects experienced a clinically important increase (≥20 %) in 6MWD. Linear mixed models of gait speed, dorsiflexion AROM, 6MWD, and FM-LM scores suggest that BCI-FES therapy is associated with an increase in lower motor performance at a statistically, yet not clinically, significant level. CONCLUSION: BCI-FES therapy is safe. If it is shown to improve post-stroke gait function in future studies, it could provide a new gait rehabilitation option for severely impaired patients. Formal clinical trials are warranted.


Asunto(s)
Interfaces Cerebro-Computador , Terapia por Estimulación Eléctrica/métodos , Trastornos Neurológicos de la Marcha/etiología , Trastornos Neurológicos de la Marcha/rehabilitación , Modalidades de Fisioterapia/efectos adversos , Modalidades de Fisioterapia/instrumentación , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Terapia por Estimulación Eléctrica/instrumentación , Electroencefalografía , Estudios de Factibilidad , Femenino , Pie/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Seguridad del Paciente , Rango del Movimiento Articular , Reproducibilidad de los Resultados , Resultado del Tratamiento , Caminata
13.
Neuroimage ; 101: 695-703, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25094020

RESUMEN

Brain machine interfaces (BMIs) have the potential to provide intuitive control of neuroprostheses to restore grasp to patients with paralyzed or amputated upper limbs. For these neuroprostheses to function, the ability to accurately control grasp force is critical. Grasp force can be decoded from neuronal spikes in monkeys, and hand kinematics can be decoded using electrocorticogram (ECoG) signals recorded from the surface of the human motor cortex. We hypothesized that kinetic information about grasping could also be extracted from ECoG, and sought to decode continuously-graded grasp force. In this study, we decoded isometric pinch force with high accuracy from ECoG in 10 human subjects. The predicted signals explained from 22% to 88% (60 ± 6%, mean ± SE) of the variance in the actual force generated. We also decoded muscle activity in the finger flexors, with similar accuracy to force decoding. We found that high gamma band and time domain features of the ECoG signal were most informative about kinetics, similar to our previous findings with intracortical LFPs. In addition, we found that peak cortical representations of force applied by the index and little fingers were separated by only about 4mm. Thus, ECoG can be used to decode not only kinematics, but also kinetics of movement. This is an important step toward restoring intuitively-controlled grasp to impaired patients.


Asunto(s)
Mapeo Encefálico/métodos , Electroencefalografía/métodos , Contracción Isométrica/fisiología , Corteza Motora/fisiología , Músculo Esquelético/fisiología , Adulto , Electrodos Implantados , Electromiografía , Femenino , Ritmo Gamma/fisiología , Mano/fisiología , Humanos , Cinética , Masculino , Persona de Mediana Edad , Adulto Joven
14.
J Virol ; 87(15): 8779-91, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23740979

RESUMEN

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of primary effusion lymphoma (PEL), multicentric Castleman's disease (MCD), and the inflammation-driven neoplasm Kaposi's sarcoma (KS). A triad of processes, including abnormal proliferation of endothelial cells, aberrant angiogenesis, and chronic inflammation, characterize KS lesions. STAT3 is a key transcription factor governing these processes, and deregulation of STAT3 activity is linked to a wide range of cancers, including PEL and KS. Using primary human endothelial cells (ECs), I demonstrate that KSHV infection modulated STAT3 activation in two ways: (i) KSHV induced uncoupling of canonical tyrosine (Y) and serine (S) phosphorylation events while (ii) concomitantly inducing the phosphorylation and inactivation of TRIM28 (also known as KAP-1 or TIF-1ß), a newly identified negative regulator of STAT3 activity. KSHV infection of primary ECs induced chronic STAT3 activation characterized by a shift from the canonical dual P-STAT3 Y705 S727 form to a mono P-STAT3 S727 form. Expression of the latent protein kaposin B promoted the unique phosphorylation of STAT3 at S727, in the absence of Y705, activated the host kinase mitogen-activated protein kinase-activated protein (MAPKAP) kinase 2 (MK2), and stimulated increased expression of STAT3-dependent genes, including CCL5, in ECs. TRIM28-mediated repression of STAT3 is relieved by phosphorylation of S473, and in vitro kinase assays identified TRIM28 S473 as a bona fide target of MK2. Together, these data suggest that kaposin B significantly contributes to the chronic inflammatory environment that is a hallmark of KS by unique activation of the proto-oncogene STAT3, coupled with MK2-mediated inactivation of the STAT3 transcriptional repressor TRIM28.


Asunto(s)
Herpesvirus Humano 8/fisiología , Interacciones Huésped-Patógeno , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Represoras/antagonistas & inhibidores , Factor de Transcripción STAT3/metabolismo , Proteínas Virales/metabolismo , Células Cultivadas , Células Endoteliales/virología , Humanos , Proto-Oncogenes Mas , Proteína 28 que Contiene Motivos Tripartito
15.
Biol Lett ; 10(6)2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24899682

RESUMEN

Most genetic studies of Holocene fauna have been performed with ancient samples from dry and cold regions, in which preservation of fossils is facilitated and molecular damage is reduced. Ancient DNA work from tropical regions has been precluded owing to factors that limit DNA preservation (e.g. temperature, hydrolytic damage). We analysed ancient DNA from rodent jawbones identified as Ototylomys phyllotis, found in Holocene and Late Pleistocene stratigraphic layers from Loltún, a humid tropical cave located in the Yucatan peninsula. We extracted DNA and amplified six short overlapping fragments of the cytochrome b gene, totalling 666 bp, which represents an unprecedented success considering tropical ancient DNA samples. We performed genetic, phylogenetic and divergence time analyses, combining sequences from ancient and modern O. phyllotis, in order to assess the ancestry of the Loltún samples. Results show that all ancient samples fall into a unique clade that diverged prior to the divergence of the modern O. phyllotis, supporting it as a distinct Pleistocene form of the Ototylomys genus. Hence, this rodent's tale suggests that the sister group to modern O. phyllotis arose during the Miocene-Pliocene, diversified during the Pleistocene and went extinct in the Holocene.


Asunto(s)
Arvicolinae/genética , Evolución Molecular , Fósiles , Animales , Citocromos b/genética , ADN/genética , México , Filogenia , Análisis de Secuencia de ADN , Factores de Tiempo , Clima Tropical
16.
J Virol ; 86(16): 8859-71, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22696654

RESUMEN

During lytic Kaposi's sarcoma-associated herpesvirus (KSHV) infection, host gene expression is severely restricted by a process of global mRNA degradation known as host shutoff, which rededicates translational machinery to the expression of viral proteins. A subset of host mRNAs is spared from shutoff, and a number of these contain cis-acting AU-rich elements (AREs) in their 3' untranslated regions. AREs are found in labile mRNAs encoding cytokines, growth factors, and proto-oncogenes. Activation of the p38/MK2 signal transduction pathway reverses constitutive decay of ARE-mRNAs, resulting in increased protein production. The viral G-protein-coupled receptor (vGPCR) is thought to play an important role in promoting the secretion of angiogenic molecules from KSHV-infected cells during lytic replication, but to date it has not been clear how vGPCR circumvents host shutoff. Here, we demonstrate that vGPCR activates the p38/MK2 pathway and stabilizes ARE-mRNAs, augmenting the levels of their protein products. Using MK2-deficient cells, we demonstrate that MK2 is essential for maximal vGPCR-mediated ARE-mRNA stabilization. ARE-mRNAs are normally delivered to cytoplasmic ribonucleoprotein granules known as processing bodies (PBs) for translational silencing and decay. We demonstrate that PB formation is prevented during KSHV lytic replication or in response to vGPCR-mediated activation of RhoA subfamily GTPases. Together, these data show for the first time that vGPCR impacts gene expression at the posttranscriptional level, coordinating an attack on the host mRNA degradation machinery. By suppressing ARE-mRNA turnover, vGPCR may facilitate escape of certain target mRNAs from host shutoff and allow secretion of angiogenic factors from lytically infected cells.


Asunto(s)
Herpesvirus Humano 8/fisiología , Interacciones Huésped-Patógeno , Estabilidad del ARN , Receptores de Quimiocina/metabolismo , Replicación Viral , Expresión Génica , Células HeLa , Humanos , Sistema de Señalización de MAP Quinasas
17.
J Neuroeng Rehabil ; 10: 77, 2013 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-23866985

RESUMEN

BACKGROUND: Spinal cord injury (SCI) can leave the affected individuals with paraparesis or paraplegia, thus rendering them unable to ambulate. Since there are currently no restorative treatments for this population, novel approaches such as brain-controlled prostheses have been sought. Our recent studies show that a brain-computer interface (BCI) can be used to control ambulation within a virtual reality environment (VRE), suggesting that a BCI-controlled lower extremity prosthesis for ambulation may be feasible. However, the operability of our BCI has not yet been tested in a SCI population. METHODS: Five participants with paraplegia or tetraplegia due to SCI underwent a 10-min training session in which they alternated between kinesthetic motor imagery (KMI) of idling and walking while their electroencephalogram (EEG) were recorded. Participants then performed a goal-oriented online task, where they utilized KMI to control the linear ambulation of an avatar while making 10 sequential stops at designated points within the VRE. Multiple online trials were performed in a single day, and this procedure was repeated across 5 experimental days. RESULTS: Classification accuracy of idling and walking was estimated offline and ranged from 60.5% (p = 0.0176) to 92.3% (p = 1.36×10-20) across participants and days. Offline analysis revealed that the activation of mid-frontal areas mostly in the µ and low ß bands was the most consistent feature for differentiating between idling and walking KMI. In the online task, participants achieved an average performance of 7.4±2.3 successful stops in 273±51 sec. These performances were purposeful, i.e. significantly different from the random walk Monte Carlo simulations (p<0.01), and all but one participant achieved purposeful control within the first day of the experiments. Finally, all participants were able to maintain purposeful control throughout the study, and their online performances improved over time. CONCLUSIONS: The results of this study demonstrate that SCI participants can purposefully operate a self-paced BCI walking simulator to complete a goal-oriented ambulation task. The operation of the proposed BCI system requires short training, is intuitive, and robust against participant-to-participant and day-to-day neurophysiological variations. These findings indicate that BCI-controlled lower extremity prostheses for gait rehabilitation or restoration after SCI may be feasible in the future.


Asunto(s)
Interfaces Cerebro-Computador , Neurorretroalimentación/métodos , Traumatismos de la Médula Espinal/rehabilitación , Terapia de Exposición Mediante Realidad Virtual/métodos , Caminata/fisiología , Adulto , Electroencefalografía , Humanos , Imágenes en Psicoterapia/métodos , Masculino , Persona de Mediana Edad , Adulto Joven
18.
J Neuroeng Rehabil ; 10: 111, 2013 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-24321081

RESUMEN

BACKGROUND: Excessive reliance on wheelchairs in individuals with tetraplegia or paraplegia due to spinal cord injury (SCI) leads to many medical co-morbidities, such as cardiovascular disease, metabolic derangements, osteoporosis, and pressure ulcers. Treatment of these conditions contributes to the majority of SCI health care costs. Restoring able-body-like ambulation in this patient population can potentially reduce the incidence of these medical co-morbidities, in addition to increasing independence and quality of life. However, no biomedical solution exists that can reverse this loss of neurological function, and hence novel methods are needed. Brain-computer interface (BCI) controlled lower extremity prostheses may constitute one such novel approach. METHODS: One able-bodied subject and one subject with paraplegia due to SCI underwent electroencephalogram (EEG) recordings while engaged in alternating epochs of idling and walking kinesthetic motor imagery (KMI). These data were analyzed to generate an EEG prediction model for online BCI operation. A commercial robotic gait orthosis (RoGO) system (suspended over a treadmill) was interfaced with the BCI computer to allow for computerized control. The subjects were then tasked to perform five, 5-min-long online sessions where they ambulated using the BCI-RoGO system as prompted by computerized cues. The performance of this system was assessed with cross-correlation analysis, and omission and false alarm rates. RESULTS: The offline accuracy of the EEG prediction model averaged 86.30% across both subjects (chance: 50%). The cross-correlation between instructional cues and the BCI-RoGO walking epochs averaged across all subjects and all sessions was 0.812 ± 0.048 (p-value <10(-4)). Also, there were on average 0.8 false alarms per session and no omissions. CONCLUSION: These results provide preliminary evidence that restoring brain-controlled ambulation after SCI is feasible. Future work will test the function of this system in a population of subjects with SCI. If successful, this may justify the future development of BCI-controlled lower extremity prostheses for free overground walking for those with complete motor SCI. Finally, this system can also be applied to incomplete motor SCI, where it could lead to improved neurological outcomes beyond those of standard physiotherapy.


Asunto(s)
Tirantes , Interfaces Cerebro-Computador , Marcha/fisiología , Robótica/métodos , Traumatismos de la Médula Espinal/rehabilitación , Adulto , Electroencefalografía , Humanos , Imaginación , Masculino , Paraplejía/etiología , Paraplejía/rehabilitación , Traumatismos de la Médula Espinal/complicaciones , Caminata/fisiología
19.
Prim Care Respir J ; 22(4): 439-48, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24186700

RESUMEN

BACKGROUND: Efficacy trials suggest that extra-fine particle beclometasone dipropionate-formoterol (efBDP-FOR) is comparable to fluticasone propionate-salmeterol (FP-SAL) in preventing asthma exacerbations at a clinically equivalent dosage. However, switching from FP-SAL to efBDP-FOR has not been evaluated in real-world asthma patients. AIMS: The REACH (Real-world Effectiveness in Asthma therapy of Combination inHalers) study investigated the clinical and cost effectiveness of switching typical asthma patients from FP-SAL to efBDP-FOR. METHODS: A retrospective matched (1:3) observational study of 1,528 asthma patients aged 18-80 years from clinical practice databases was performed. Patients remaining on FP-SAL (n=1,146) were compared with those switched to efBDP-FOR at an equivalent or lower inhaled corticosteroid (ICS) dosage (n=382). Clinical and economic outcomes were compared between groups for the year before and after the switch. Non-inferiority (at least equivalence) of efBDP-FOR was tested against FP-SAL by comparing exacerbation rates during the outcome year. RESULTS: efBDP-FOR was non-inferior to FP-SAL (adjusted exacerbation rate ratio 1.01 (95% CI 0.74 to 1.37)). Switching to efBDP-FOR resulted in significantly better (p<0.05) odds of achieving overall asthma control (no asthma-related hospitalisations, bronchial infections, or acute oral steroids; salbutamol ≤200µg/day) and lower daily short-acting ß2-agonist usage at a lower daily ICS dosage (mean -130µg/day FP equivalents; p<0.001). It also reduced mean asthma-related healthcare costs by £93.63/patient/year (p<0.001). CONCLUSIONS: Asthma patients may be switched from FP-SAL to efBDP-FOR at an equivalent or lower ICS dosage with no reduction in clinical effectiveness but a significant reduction in cost.


Asunto(s)
Albuterol/análogos & derivados , Androstadienos/uso terapéutico , Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Beclometasona/uso terapéutico , Etanolaminas/uso terapéutico , Administración por Inhalación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Albuterol/economía , Albuterol/uso terapéutico , Androstadienos/economía , Antiasmáticos/economía , Asma/economía , Beclometasona/economía , Análisis Costo-Beneficio , Combinación de Medicamentos , Costos de los Medicamentos , Sustitución de Medicamentos/economía , Etanolaminas/economía , Femenino , Combinación Fluticasona-Salmeterol , Fumarato de Formoterol , Costos de la Atención en Salud , Servicios de Salud/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
20.
Biomed Eng Educ ; : 1-15, 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-37363619

RESUMEN

In this paper, we altered an in-person high school tissue engineering program to create a virtual course. Through this alteration, we aimed to show that online programs can still be engaging and at the same time provide greater accessibility and flexibility to students. This was achieved through utilizing Google classroom as a virtual platform for students to engage with course modules and assessments. After analyzing pre- and post-program survey responses in both the in-person and online offerings of the CardioStart program, it was found that students improved in their understanding of all of the tissue engineering topics that were introduced in the programs. Furthermore, when comparing the results from the in-person versus online offerings of the program, it was found that the level of student understanding and learning of these topics was similar across the in-person and online programs. We were also able to engage five times the number of students online as compared to the in-person program, which was conducted yearly for six summers. However, many students indicated that their experience would have been better if hands-on activities were included to supplement their knowledge of cell culture techniques after completing the course. The online program improved accessibility and scalability of the program compared to in-person workshops. Future work will consist of bridging this virtual course and the hands-on experiments performed during the in-person program to provide interested students access to laboratory experiences.

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