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- 2021-2025 Strategic Plan, Virginia Tech Carilion School of Medicine(Virginia Tech Carilion School of Medicine, 2021)The VTCSOM Strategic Plan will guide our medical school into a vibrant future. In collaboration with our parent university (Virginia Tech), our health system partner (Carilion Clinic) and other community stakeholders, we will understand the challenges and opportunities we face as a medical school and respond with a comprehensive plan to achieve feasible, sustainable and measurable objectives.
- 3D electron microscopy and volume-based bouton sorting reveal the selectivity of inputs onto geniculate relay cell and interneuron dendrite segmentsMaher, Erin E.; Briegel, Alex C.; Imtiaz, Shahrozia; Fox, Michael A.; Golino, Hudson; Erisir, Alev (Frontiers, 2023-03)IntroductionThe visual signals evoked at the retinal ganglion cells are modified and modulated by various synaptic inputs that impinge on lateral geniculate nucleus cells before they are sent to the cortex. The selectivity of geniculate inputs for clustering or forming microcircuits on discrete dendritic segments of geniculate cell types may provide the structural basis for network properties of the geniculate circuitry and differential signal processing through the parallel pathways of vision. In our study, we aimed to reveal the patterns of input selectivity on morphologically discernable relay cell types and interneurons in the mouse lateral geniculate nucleus. MethodsWe used two sets of Scanning Blockface Electron Microscopy (SBEM) image stacks and Reconstruct software to manually reconstruct of terminal boutons and dendrite segments. First, using an unbiased terminal sampling (UTS) approach and statistical modeling, we identified the criteria for volume-based sorting of geniculate boutons into their putative origins. Geniculate terminal boutons that were sorted in retinal and non-retinal categories based on previously described mitochondrial morphology, could further be sorted into multiple subpopulations based on their bouton volume distributions. Terminals deemed non-retinal based on the morphological criteria consisted of five distinct subpopulations, including small-sized putative corticothalamic and cholinergic boutons, two medium-sized putative GABAergic inputs, and a large-sized bouton type that contains dark mitochondria. Retinal terminals also consisted of four distinct subpopulations. The cutoff criteria for these subpopulations were then applied to datasets of terminals that synapse on reconstructed dendrite segments of relay cells or interneurons. ResultsUsing a network analysis approach, we found an almost complete segregation of retinal and cortical terminals on putative X-type cell dendrite segments characterized by grape-like appendages and triads. On these cells, interneuron appendages intermingle with retinal and other medium size terminals to form triads within glomeruli. In contrast, a second, presumed Y-type cell displayed dendrodendritic puncta adherentia and received all terminal types without a selectivity for synapse location; these were not engaged in triads. Furthermore, the contribution of retinal and cortical synapses received by X-, Y- and interneuron dendrites differed such that over 60% of inputs to interneuron dendrites were from the retina, as opposed to 20% and 7% to X- and Y-type cells, respectively. ConclusionThe results underlie differences in network properties of synaptic inputs from distinct origins on geniculate cell types.
- 3D models of glioblastoma interaction with cortical cellsAbedin, Md Joynal; Michelhaugh, Sharon K.; Mittal, Sandeep; Berdichevsky, Yevgeny (Frontiers, 2023-03-09)Introduction: Glioblastoma (GBM) invasiveness and ability to infiltrate deep into the brain tissue is a major reason for the poor patient prognosis for this type of brain cancer. Behavior of glioblastoma cells, including their motility, and expression of invasion-promoting genes such as matrix metalloprotease-2 (MMP2), are strongly influenced by normal cells found in the brain parenchyma. Cells such as neurons may also be influenced by the tumor, as many glioblastoma patients develop epilepsy. In vitro models of glioblastoma invasiveness are used to supplement animal models in a search for better treatments, and need to combine capability for high-throughput experiments with capturing bidirectional interactions between GBM and brain cells.Methods: In this work, two 3D in vitro models of GBM-cortical interactions were investigated. A matrix-free model was created by co-culturing GBM and cortical spheroids, and a matrix-based model was created by embedding cortical cells and a GBM spheroid in Matrigel.Results: Rapid GBM invasion occurred in the matrix-based model, and was enhanced by the presence of cortical cells. Little invasion occurred in the matrix-free model. In both types of models, presence of GBM cells resulted in a significant increase in paroxysmal neuronal activity.Discussion: Matrix-based model may be better suited for studying GBM invasion in an environment that includes cortical cells, while matrix-free model may be useful in investigation of tumor-associated epilepsy.
- A 4-year longitudinal neuroimaging study of cognitive control using latent growth modeling: developmental changes and brain-behavior associationsKim-Spoon, Jungmeen; Herd, Toria; Brieant, Alexis; Elder, Jacob; Lee, Jacob; Deater-Deckard, Kirby; Casas, Brooks (2021-08-15)Despite theoretical models suggesting developmental changes in neural substrates of cognitive control in adolescence, empirical research has rarely examined intraindividual changes in cognitive control-related brain activation using multi-wave multivariate longitudinal data. We used longitudinal repeated measures of brain activation and behavioral performance during the multi-source interference task (MSIT) from 167 adolescents (53% male) who were assessed annually over four years from ages 13 to 17 years. We applied latent growth modeling to delineate the pattern of brain activation changes over time and to examine longitudinal associations between brain activation and behavioral performance. We identified brain regions that showed differential change patterns: (1) the fronto-parietal regions that involved bilateral insula, bilateral middle frontal gyrus, left pre-supplementary motor area, left inferior parietal lobule, and right precuneus; and (2) the rostral anterior cingulate cortex (rACC) region. Longitudinal confirmatory factor analyses of the fronto-parietal regions revealed strong measurement invariance across time implying that multivariate functional magnetic resonance imaging data during cognitive control can be measured reliably over time. Latent basis growth models indicated that fronto-parietal activation decreased over time, whereas rACC activation increased over time. In addition, behavioral performance data, age-related improvement was indicated by a decreasing trajectory of intraindividual variability in response time across four years. Testing longitudinal brain-behavior associations using multivariate growth models revealed that better behavioral cognitive control was associated with lower fronto-parietal activation, but the change in behavioral performance was not related to the change in brain activation. The current findings suggest that reduced effects of cognitive interference indicated by fronto-parietal recruitment may be a marker of a maturing brain that underlies better cognitive control performance during adolescence.
- A 52-Year-Old HIV-Positive Man with Abdominal PainMehmood, Tashfeen; Chua, Matt J.; Khasawneh, Faisal A. (Hindawi, 2015-01-01)
- Aberrant early growth of individual trigeminal sensory and motor axons in a series of mouse genetic models of 22q11.2 deletion syndromeMotahari, Zahra; Maynard, Thomas M.; Popratiloff, Anastas; Moody, Sally A.; LaMantia, Anthony-Samuel (2020-09-15)We identified divergent modes of initial axon growth that prefigure disrupted differentiation of the trigeminal nerve (CN V), a cranial nerve essential for suckling, feeding and swallowing (S/F/S), a key innate behavior compromised in multiple genetic developmental disorders including DiGeorge/22q11.2 Deletion Syndrome (22q11.2 DS). We combined rapid in vivo labeling of single CN V axons in LgDel(+/-) mouse embryos, a genomically accurate 22q11.2DS model, and 3D imaging to identify and quantify phenotypes that could not be resolved using existing methods. We assessed these phenotypes in three 22q11.2-related genotypes to determine whether individual CN V motor and sensory axons wander, branch and sprout aberrantly in register with altered anterior-posterior hindbrain patterning and gross morphological disruption of CN V seen in LgDel(+/-). In the additional 22q11.2-related genotypes: Tbx1(+/-), Ranbp1(+/-), Ranbp1(+/-) and LgDel(+/-):Raldh2(+/-); axon phenotypes are seen when hindbrain patterning and CN V gross morphology is altered, but not when it is normal or restored toward WT. This disordered growth of CN V sensory and motor axons, whose appropriate targeting is critical for optimal S/F/S, may be an early, critical determinant of imprecise innervation leading to inefficient oropharyngeal function associated with 22q11.2 deletion from birth onward.
- Aberrant placental immune parameters in the feline immunodeficiency virus (FIV)-infected cat suggest virus-induced changes in T cell functionChumbley, Lyndon B.; Boudreaux, Crystal E.; Coats, Karen S. (2013-07-19)Background Immune activity during pregnancy must be tightly regulated to ensure successful pregnancy. This regulation includes the suppression of inflammatory activity that could target the semi-allogeneic fetus. Tregs are immunosuppressive; Th17 cells are pro-inflammatory. A precise balance in the two cell populations is critical to pregnancy maintenance, while dysregulation in this balance accompanies compromised pregnancy in humans and mice. FIV is known to target Tregs preferentially in the infected cat. Therefore, it may be hypothesized that FIV infection alters the placental Treg/Th17 cell balance resulting in aberrant immunomodulator expression by these cells and consequent pregnancy perturbation. Methods RNA was purified from random sections of whole placental tissues collected from both uninfected and FIV-infected queens at early pregnancy, including tissues from viable and nonviable fetuses. Real time qPCR was performed to quantify expression of intranuclear markers of Tregs (FoxP3) and Th17 cells (RORΩ); cytokine products of Tregs (IL-10 and TGF-β), Th17 cells (IL-2, IL-6, and IL-17a), and macrophages (IL-1β); and the FIV gag gene. Pairwise comparisons were made to evaluate coexpression patterns between the cytokines and between the cytokines and the virus. Results Both FoxP3 and RORΩ were reduced in placentas of infected animals. Neither infection status nor fetal viability affected placental expression of IL-1β. However, fetal nonviability was associated with reduced levels of all other cytokines. Infection and fetal nonviability impacted coexpression of various cytokine pairs. No obvious bias toward Treg or Th17 cells was observed. Conclusions FIV infection coupled with fetal nonviability alters expression patterns of T cell cytokines. These data suggest that functionally altered placental T cell leukocyte populations may occur in the infected queen and possibly contribute to fetal nonviability.
- Access to Autism Spectrum Disorder Services for Rural Appalachian CitizensScarpa, Angela; Jensen, Laura S.; Gracanin, Denis; Ramey, Sharon L.; Dahiya, Angela V.; Ingram, L. Maria; Albright, Jordan; Gatto, Alyssa J.; Scott, Jen Pollard; Ruble, Lisa (2020-01)Background: Low-resource rural communities face significant challenges regarding availability and adequacy of evidence-based services. Purposes: With respect to accessing evidence-based services for Autism Spectrum Disorder (ASD), this brief report summarizes needs of rural citizens in the South-Central Appalachian region, an area notable for persistent health disparities. Methods: A mixed-methods approach was used to collect quantitative and qualitative data during focus groups with 33 service providers and 15 caregivers of children with ASD in rural southwest Virginia. Results: Results supported the barriers of availability and affordability of ASD services in this region, especially relating to the need for more ASD-trained providers, better coordination and navigation of services, and addition of programs to assist with family financial and emotional stressors. Results also suggested cultural attitudes related to autonomy and trust towards outside professionals that may prevent families from engaging in treatment. Implications: Relevant policy recommendations are discussed related to provider incentives, insurance coverage, and telehealth. Integration of autism services into already existing systems and multicultural sensitivity of providers are also implicated.
- Accurate human microsatellite genotypes from high-throughput resequencing data using informed error profilesHighnam, Gareth; Franck, Christopher T.; Martin, Andy; Stephens, Calvin; Puthige, Ashwin; Mittelman, David (Oxford University Press, 2013-01)Repetitive sequences are biologically and clinically important because they can influence traits and disease, but repeats are challenging to analyse using short-read sequencing technology. We present a tool for genotyping microsatellite repeats called RepeatSeq, which uses Bayesian model selection guided by an empirically derived error model that incorporates sequence and read properties. Next, we apply RepeatSeq to high-coverage genomes from the 1000 Genomes Project to evaluate performance and accuracy. The software uses common formats, such as VCF, for compatibility with existing genome analysis pipelines. Source code and binaries are available at http://github.com/adaptivegenome/repeatseq.
- Acetylcholine Receptor Activation as a Modulator of Glioblastoma InvasionThompson, Emily G.; Sontheimer, Harald (MDPI, 2019-10-05)Grade IV astrocytomas, or glioblastomas (GBMs), are the most common malignant primary brain tumor in adults. The median GBM patient survival of 12–15 months has remained stagnant, in spite of treatment strategies, making GBMs a tremendous challenge clinically. This is at least in part due to the complex interaction of GBM cells with the brain microenvironment and their tendency to aggressively infiltrate normal brain tissue. GBMs frequently invade supratentorial brain regions that are richly innervated by neurotransmitter projections, most notably acetylcholine (ACh). Here, we asked whether ACh signaling influences the biology of GBMs. We examined the expression and function of known ACh receptors (AChRs) in large GBM datasets, as well as, human GBM cell lines and patient-derived xenograft lines. Using RNA-Seq data from the “The Cancer Genome Atlas” (TCGA), we confirmed the expression of AChRs and demonstrated the functionality of these receptors in GBM cells with time-lapse calcium imaging. AChR activation did not alter cell proliferation or migration, however, it significantly increased cell invasion through complex extracellular matrices. This was due to the enhanced activity of matrix metalloproteinase-9 (MMP-9) from GBM cells, which we found to be dependent on an intracellular calcium-dependent mechanism. Consistent with these findings, AChRs were significantly upregulated in regions of GBM infiltration in situ (Ivy Glioblastoma Atlas Project) and elevated expression of muscarinic AChR M3 correlated with reduced patient survival (TCGA). Data from the Repository for Molecular Brain Neoplasia Data (REMBRANDT) dataset also showed the co-expression of choline transporters, choline acetyltransferase, and vesicular acetylcholine transporters, suggesting that GBMs express all the proteins required for ACh synthesis and release. These findings identify ACh as a modulator of GBM behavior and posit that GBMs may utilize ACh as an autocrine signaling molecule.
- An Acoustic Sensor for Airflow in Pediatric Artificial AirwaysGooty, Vasu; Harris, Charles; Muelenaer, Andre A.; Watson, Brian; Safford, Shawn D. (Elsevier, 2015-01-06)Pulmonary hyalinizing granuloma (PHG) is a rare benign pulmonary nodular lesion of unknown etiology. We present a case of a 5-year-old boy who was found to have a chest mass while being evaluated for abdominal pain. He underwent a CXR and CT scan that showed popcorn calcifications in the right posterior mediastinum and within the hilum of right lung. These lesions were suspicious for benign calcified lymph nodes and follow-up chest CT after 3.5 months showed no interval changes in the calcified mediastinal masses. Extensive testing ruled out infectious diseases and malignancies. Given the unknown etiology of the lesions, he underwent VATS biopsy that demonstrated a nodular lesion characterized by a peripheral rim of fibrous tissue and central zone of necrosis and calcification, findings consistent with hyalinizing granuloma. PHG is extremely rare in pediatric age group. Although diagnosis of this condition is made by radiological and histopathological findings, it is important to rule out other causes of chest masses. Most of the patients usually have good prognosis with this rare disorder.
- Active inference and agency: optimal control without cost functionsFriston, Karl J.; Samothrakis, Spyridon; Montague, P. Read (Springer, 2012-08-03)This paper describes a variational free-energy formulation of (partially observable) Markov decision problems in decision making under uncertainty. We show that optimal control can be cast as active inference. In active inference, both action and posterior beliefs about hidden states minimise a free energy bound on the negative log-likelihood of observed states, under a generative model. In this setting, reward or cost functions are absorbed into prior beliefs about state transitions and terminal states. Effectively, this converts optimal control into a pure inference problem, enabling the application of standard Bayesian filtering techniques.We then consider optimal trajectories that rest on posterior beliefs about hidden states in the future. Crucially, this entails modelling control as a hidden state that endows the generative model with a representation of agency. This leads to a distinction between models with and without inference on hidden control states; namely, agency-free and agency-based models, respectively.
- Acutely enhancing affective state and social connection following an online dance intervention during the COVID-19 social isolation crisisHumphries, Ashlee; Tasnim, Noor; Rugh, Rachel; Patrick, Morgan; Basso, Julia C. (2023-01-16)The COVID-19 pandemic has forced many throughout the world to isolate themselves from their respective communities to stop the spread of disease. Although this form of distancing can prevent the contraction of a virus, it results in social isolation and physical inactivity. Consequently, our communities have become heavily reliant on digital solutions to foster social connection and increase physical activity when forced to isolate. Dance is a multidimensional form of physical activity that includes sensory, motor, cognitive, rhythmic, creative, and social elements. Long-term, interventional studies in dance have shown positive effects on both mental and social health; however, little has been done to examine the acute effects and no studies to date have explored the relationship between the affective state and social outcomes of dance. We examined the hypothesis that online dance is associated with improvements in affective state and social connection during a time of social isolation, namely, the COVID-19 crisis. Healthy adults (age ≥ 18; n = 47) engaged in a single session of 60 min of self-selected online dance, completing a series of validated self-reported questionnaires before and after class. We found that online dance was associated with improvements in affective state as measured by increased positive affect and self-esteem and decreased negative affect and depressive symptoms. Additionally, online dance was associated with improvements in social and community connectedness. Further, we found that those who experienced the largest increases in self-esteem and decreases in negative affect demonstrated the largest gains in social connectivity. Although in-person dance classes may be optimal for formalized dance training, online dance instruction offers an accessible platform that can provide mental and social health benefits during the COVID-19 social isolation crisis. We conclude that through online dance, individuals can experience a connection between the body, mind, and community.
- Adenovirus transduction to express human ACE2 causes obesity-specific morbidity in mice, impeding studies on the effect of host nutritional status on SARS-CoV-2 pathogenesisRai, Pallavi; Chuong, Christina; LeRoith, Tanya; Smyth, James W.; Panov, Julia; Levi, Moshe; Kehn-Hall, Kylene; Duggal, Nisha K.; Weger-Lucarelli, James (Elsevier, 2021-11-01)The COVID-19 pandemic has paralyzed the global economy and resulted in millions of deaths globally. People with co-morbidities like obesity, diabetes and hypertension are at an increased risk for severe COVID-19 illness. This is of overwhelming concern because 42% of Americans are obese, 30% are pre-diabetic and 9.4% have clinical diabetes. Here, we investigated the effect of obesity on disease severity following SARS-CoV-2 infection using a well-established mouse model of diet-induced obesity. Diet-induced obese and lean control C57BL/6 N mice, transduced for ACE2 expression using replication-defective adenovirus, were infected with SARS-CoV-2, and monitored for lung pathology, viral titers, and cytokine expression. No significant differences in tissue pathology or viral replication was observed between AdV transduced lean and obese groups, infected with SARS-CoV-2, but certain cytokines were expressed more significantly in infected obese mice compared to the lean ones. Notably, significant weight loss was observed in obese mice treated with the adenovirus vector, independent of SARS-CoV-2 infection, suggesting an obesity-dependent morbidity induced by the vector. These data indicate that the adenovirus-transduced mouse model of SARS-CoV-2 infection, as described here and elsewhere, may be inappropriate for nutrition studies.
- The adhesion function of the sodium channel beta subunit (beta 1) contributes to cardiac action potential propagationVeeraraghavan, Rengasayee; Hoeker, Gregory S.; Alvarez-Laviada, Anita; Hoagland, Daniel T.; Wan, Xiaoping; King, D. Ryan; Sanchez-Alonso, Jose; Chen, Chunling; Jourdan, L. Jane; Isom, Lori L.; Deschenes, Isabelle; Smith, James W.; Gorelik, Julia; Poelzing, Steven; Gourdie, Robert G. (2018-08-14)Computational modeling indicates that cardiac conduction may involve ephaptic coupling - intercellular communication involving electrochemical signaling across narrow extracellular clefts between cardiomyocytes. We hypothesized that beta 1(SCN1B) - mediated adhesion scaffolds trans-activating Na(V)1.5 (SCN5A) channels within narrow (<30 nm) perinexal clefts adjacent to gap junctions (GJs), facilitating ephaptic coupling. Super-resolution imaging indicated preferential beta 1 localization at the perinexus, where it co-locates with Na(V)1.5. Smart patch clamp (SPC) indicated greater sodium current density (I-Na) at perinexi, relative to non-junctional sites. A novel, rationally designed peptide, beta adp1, potently and selectively inhibited beta 1-mediated adhesion, in electric cell-substrate impedance sensing studies. beta adp1 significantly widened perinexi in guinea pig ventricles, and selectively reduced perinexal I-Na, but not whole cell I-Na, in myocyte monolayers. In optical mapping studies, beta adp1 precipitated arrhythmogenic conduction slowing. In summary, beta 1-mediated adhesion at the perinexus facilitates action potential propagation between cardiomyocytes, and may represent a novel target for anti-arrhythmic therapies.
- Adult Intestinal Intussusception Caused by the Gastrojejunostomy Tube: An Endoscopically Treatable PhenomenonZhang, Kermit S.; Bansal, Jash; Bansal, Anmol; Chitnavis, Vikas (Hindawi, 2021-06-11)Adult duodenoduodenal intussusception is extremely rare due to the retroperitoneal fixation of the second, third, and fourth parts of the duodenum. A majority of clinically significant intussusception with identifiable etiologies is typically neoplastic with more rare causes including retained food and indwelling enteral tubes, specifically with gastrojejunostomy (GJ) tubes. Herein, we discuss the case of a 23-year-old male who developed duodenoduodenal intussusception upon a PEGJ placement with associated gastroduodenal dilation and telescope phenomenon. To the best of our knowledge, there are no reports of intussusception found to be caused by GJ tubes in the adult population. The reported patient was found to have a 4-cm enteroenteric intussusception without obstruction or ischemia with bowel thickening proximal to the pathology. Although adult intussusception cases are typically managed surgically, we were able to reduce the intussusception via endoscopy due to rapid diagnosis upon presentation and intervention before the bowel wall could be compromised.
- Advances in Behavioral Remote Data Collection in the Home Setting: Assessing the Mother-Infant Relationship and Infant's Adaptive Behavior via Virtual VisitsShin, Eunkyung; Smith, Cynthia L.; Howell, Brittany R. (Frontiers, 2021-10-01)Psychological science is struggling with moving forward in the midst of the COVID-19 pandemic, especially due to the halting of behavioral data collection in the laboratory. Safety barriers to assessing psychological behavior in person increased the need for remote data collection in natural settings. In response to these challenges, researchers, including our team, have utilized this time to advance remote behavioral methodology. In this article, we provide an overview of our group’s strategies for remote data collection methodology and examples from our research in collecting behavioral data in the context of psychological functioning. Then, we describe the design and development of our strategies for remote data collection of mother-infant interactions, with the goal being to assess maternal sensitivity and intrusiveness, as well as infants’ adaptive behaviors in several developmental domains. During these virtual visits over Zoom, mother-infant dyads watched a book-reading video and were asked to participate in peek-a-boo, toy play, and toy removal tasks. After the behavioral tasks, a semi-structured interview (Vineland Adaptive Behavior Scale – VABS III) was conducted to assess the infant’s adaptive behavior in communication, socialization, daily living skills, and motor domains. We delineate the specific strategies we applied to integrate laboratory tasks and a semi-structured interview into remote data collection in home settings with mothers and infants. We also elaborate on issues encountered during remote data collection and how we resolved these challenges. Lastly, to inform protocols for future remote data collection, we address considerations and recommendations, as well as benefits and future directions for behavioral researchers in developmental psychology research.