16 research outputs found
Entry of Herpes Simplex Virus Type 1 (HSV-1) into the Distal Axons of Trigeminal Neurons Favors the Onset of Nonproductive, Silent Infection
Following productive, lytic infection in epithelia, herpes simplex virus type 1 (HSV-1) establishes a lifelong latent infection in sensory neurons that is interrupted by episodes of reactivation. In order to better understand what triggers this lytic/latent decision in neurons, we set up an organotypic model based on chicken embryonic trigeminal ganglia explants (TGEs) in a double chamber system. Adding HSV-1 to the ganglion compartment (GC) resulted in a productive infection in the explants. By contrast, selective application of the virus to distal axons led to a largely nonproductive infection that was characterized by the poor expression of lytic genes and the presence of high levels of the 2.0-kb major latency-associated transcript (LAT) RNA. Treatment of the explants with the immediate-early (IE) gene transcriptional inducer hexamethylene bisacetamide, and simultaneous co-infection of the GC with HSV-1, herpes simplex virus type 2 (HSV-2) or pseudorabies virus (PrV) helper virus significantly enhanced the ability of HSV-1 to productively infect sensory neurons upon axonal entry. Helper-virus-induced transactivation of HSV-1 IE gene expression in axonally-infected TGEs in the absence of de novo protein synthesis was dependent on the presence of functional tegument protein VP16 in HSV-1 helper virus particles. After the establishment of a LAT-positive silent infection in TGEs, HSV-1 was refractory to transactivation by superinfection of the GC with HSV-1 but not with HSV-2 and PrV helper virus. In conclusion, the site of entry appears to be a critical determinant in the lytic/latent decision in sensory neurons. HSV-1 entry into distal axons results in an insufficient transactivation of IE gene expression and favors the establishment of a nonproductive, silent infection in trigeminal neurons
A compositional model for CO2 flooding including CO2 equilibria between water and oil using the Peng–Robinson equation of state with the Wong–Sandler mixing rule
Growth and nutrient removal properties of the diatoms, Chaetoceros curvisetus and C. simplex under different nitrogen sources
Growth of Chlorella vulgaris on Sugarcane Vinasse: The Effect of Anaerobic Digestion Pretreatment
Global climate change and local watershed management as potential drivers of salinity variation in a tropical coastal lagoon (Laguna de Terminos, Mexico)
Insights into Dietary Switch in Cetaceans: Evidence from Molecular Evolution of Proteinases and Lipases
Single-channel EEG measurement of engagement in virtual rehabilitation: a validation study
Stroke rehabilitation suffers from low levels of patient engagement, impeding recovery. Virtual rehabilitation (VR) approaches can improve patient outcomes; however, there is limited understanding of the participant’s user experience and the field lacks a validated, objective measure of VR engagement. A neurophysiological measure of engagement in healthy adults was therefore examined, to inform future clinical studies. Twenty-four participants (Mage 26.7 years, range 18–47) interacted with a tabletop VR system (Elements DNA, or EDNA), after which they rated their experience on the presence questionnaire (PQ). Separately, participants completed tasks eliciting low (resting eyes-open and -closed) and high (EDNA VR and roller coaster simulation) levels of engagement while continuous electroencephalogram (EEG) was recorded from a single, left pre-frontal electrode. EEG differences between the resting and simulation conditions included an increase in theta power (p \u3c 0.01) and a decrease in alpha power (p \u3c 0.01). Importantly, theta power in simulation conditions correlated with PQ scores expressing the hands-on EDNA VR experience (rs = 0.38–0.48). In conclusion, the current results provide proof of concept that increased frontal theta power in healthy adults provides a valid measure of user engagement in VR simulation and participation. As the practical potential of VR is increasingly realised in stroke rehabilitation, objective EEG-based measures of engagement may provide a convenient and sensitive technique to assist in evaluating these interventions