The Impact of Vocal Tremor on Deglutition: A Pilot Study.

OBJECTIVE: Vocal tremor (VT) poses treatment challenges due to uncertain pathophysiology. VT is typically classified into two phenotypes: isolated vocal tremor (iVT) and essential tremor-related voice tremor (ETvt). The impact of phenotypes on upper aerodigestive tract physiology during swallowing remains unclear. Qualitative and quantitative measures were employed to characterize tremor phenotypes and investigate the effects on swallowing physiology. METHODS: Eleven ETvt participants (1 Male, 10 Female; x̄ age = 74) and 8 iVT participants (1 Male, 7 Female; x̄ age = 71) swallowed 20 mL boluses in cued and uncued conditions under standardized fluoroscopic visualization. Sustained/a/productions were captured to assess the rate and extent of fundamental frequency (F0) modulation. Penetration and Aspiration Scale (PAS) scores were obtained and swallowing biomechanics were captured using Swallowtail™ software. Participants also completed the Swallowing Quality of Life (SWAL-QOL) questionnaire. RESULTS: Hypopharyngeal transit was faster in both VT phenotypes compared with Swallowtail™ normative reference data. Total pharyngeal transit times, however, were only faster in patients with iVT, relative to reference data. No significant differences were observed on the SWAL-QOL or PAS between tremor phenotypes. SWAL-QOL scores revealed that these patients rarely reported dysphagia symptoms. CONCLUSIONS: Subtle differences in swallowing patterns were observed across VT phenotypes, possibly related to adaptive mechanisms resulting in quicker pharyngeal bolus transit. Most patients did not report swallowing issues or dysphagia symptoms. This study is foundational for larger studies on this challenging population. LEVEL OF EVIDENCE: 4 Laryngoscope, 2024.

Infection and chronic disease activate a systemic brain-muscle signaling axis.

Infections and neurodegenerative diseases induce neuroinflammation, but affected individuals often show nonneural symptoms including muscle pain and muscle fatigue. The molecular pathways by which neuroinflammation causes pathologies outside the central nervous system (CNS) are poorly understood. We developed multiple models to investigate the impact of CNS stressors on motor function and found that Escherichia coli infections and SARS-CoV-2 protein expression caused reactive oxygen species (ROS) to accumulate in the brain. ROS induced expression of the cytokine Unpaired 3 (Upd3) in Drosophila and its ortholog, IL-6, in mice. CNS-derived Upd3/IL-6 activated the JAK-STAT pathway in skeletal muscle, which caused muscle mitochondrial dysfunction and impaired motor function. We observed similar phenotypes after expressing toxic amyloid-ß (Aß42) in the CNS. Infection and chronic disease therefore activate a systemic brain-muscle signaling axis in which CNS-derived cytokines bypass the connectome and directly regulate muscle physiology, highlighting IL-6 as a therapeutic target to treat disease-associated muscle dysfunction.

Elevated phagocytic capacity directs innate spinal cord repair.

Immune cells elicit a continuum of transcriptional and functional states after spinal cord injury (SCI). In mammals, inefficient debris clearance and chronic inflammation impede recovery and overshadow pro-regenerative immune functions. We found that, unlike mammals, zebrafish SCI elicits transient immune activation and efficient debris clearance, without causing chronic inflammation. Single-cell transcriptomics and inducible genetic ablation showed zebrafish macrophages are highly phagocytic and required for regeneration. Cross-species comparisons between zebrafish and mammalian macrophages identified transcription and immune response regulator ( tcim ) as a macrophage-enriched zebrafish gene. Genetic deletion of zebrafish tcim impairs phagocytosis and regeneration, causes aberrant and chronic immune activation, and can be rescued by transplanting wild-type immune precursors into tcim mutants. Conversely, genetic expression of human TCIM accelerates debris clearance and regeneration by reprogramming myeloid precursors into activated phagocytes. This study establishes a central requirement for elevated phagocytic capacity to achieve innate spinal cord repair.

Functional role of myosin-binding protein H in thick filaments of developing vertebrate fast-twitch skeletal muscle.

Myosin-binding protein H (MyBP-H) is a component of the vertebrate skeletal muscle sarcomere with sequence and domain homology to myosin-binding protein C (MyBP-C). Whereas skeletal muscle isoforms of MyBP-C (fMyBP-C, sMyBP-C) modulate muscle contractility via interactions with actin thin filaments and myosin motors within the muscle sarcomere "C-zone," MyBP-H has no known function. This is in part due to MyBP-H having limited expression in adult fast-twitch muscle and no known involvement in muscle disease. Quantitative proteomics reported here reveal MyBP-H is highly expressed in prenatal rat fast-twitch muscles and larval zebrafish, suggesting a conserved role in muscle development, and promoting studies to define its function. We take advantage of the genetic control of the zebrafish model and a combination of structural, functional, and biophysical techniques to interrogate the role of MyBP-H. Transgenic, FLAG-tagged MyBP-H or fMyBP-C both localize to the C-zones in larval myofibers, whereas genetic depletion of endogenous MyBP-H or fMyBP-C leads to increased accumulation of the other, suggesting competition for C-zone binding sites. Does MyBP-H modulate contractility from the C-zone? Globular domains critical to MyBP-C's modulatory functions are absent from MyBP-H, suggesting MyBP-H may be functionally silent. However, our results suggest an active role. Small angle x-ray diffraction of intact larval tails revealed MyBP-H contributes to the compression of the myofilament lattice accompanying stretch or contraction, while in vitro motility experiments indicate MyBP-H shares MyBP-C's capacity as a molecular "brake". These results provide new insights and raise questions about the role of the C-zone during muscle development.

Path to autonomous soil sampling and analysis by ground-based robots.

Good site characterization is essential for the selection of remediation alternatives for impacted soils. The value of site characterization is critically dependent on the quality and quantity of the data collected. Current methods for characterizing impacted soils rely on expensive manual sample collection and off-site analysis. However, recent advances in terrestrial robotics and artificial intelligence offer a potentially revolutionary set of tools and methods that will help to autonomously explore natural environments, select sample locations with the highest value of information, extract samples, and analyze the data in real-time without exposing humans to potentially hazardous conditions. A fundamental challenge to realizing this potential is determining how to design an autonomous system for a given investigation with many, and often conflicting design criteria. This work presents a novel design methodology to navigate these criteria. Specifically, this methodology breaks the system into four components - sensing, sampling, mobility, and autonomy - and connects design variables to the investigation objectives and constraints. These connections are established for each component through a survey of existing technology, discussion of key technical challenges, and highlighting conditions where generality can promote multi-application deployment. An illustrative example of this design process is presented for the development and deployment of a robotic platform characterizing salt-impacted oil & gas reserve pits. After calibration, the relationship between the in situ robot chloride measurements and laboratory-based chloride measurements had a good linear relationship (R2-value = 0.861) and statistical significance (p-value = 0.003).

Myoglobin Inhibits Breast Cancer Cell Fatty Acid Oxidation and Migration via Heme-dependent Oxidant Production and Not Fatty Acid Binding.

The monomeric heme protein myoglobin (Mb), traditionally thought to be expressed exclusively in cardiac and skeletal muscle, is now known to be expressed in approximately 40% of breast tumors. While Mb expression is associated with better patient prognosis, the molecular mechanisms by which Mb limits cancer progression are unclear. In muscle, Mb's predominant function is oxygen storage and delivery, which is dependent on the protein's heme moiety. However, prior studies demonstrate that the low levels of Mb expressed in cancer cells preclude this function. Recent studies propose a novel fatty acid binding function for Mb via a lysine residue (K46) in the heme pocket. Given that cancer cells can upregulate fatty acid oxidation (FAO) to maintain energy production for cytoskeletal remodeling during cell migration, we tested whether Mb-mediated fatty acid binding modulates FAO to decrease breast cancer cell migration. We demonstrate that the stable expression of human Mb in MDA-MB-231 breast cancer cells decreases cell migration and FAO. Site-directed mutagenesis of Mb to disrupt Mb fatty acid binding did not reverse Mb-mediated attenuation of FAO or cell migration in these cells. In contrast, cells expressing Apo-Mb, in which heme incorporation was disrupted, showed a reversal of Mb-mediated attenuation of FAO and cell migration, suggesting that Mb attenuates FAO and migration via a heme-dependent mechanism rather than through fatty acid binding. To this end, we show that Mb's heme-dependent oxidant generation propagates dysregulated gene expression of migratory genes, and this is reversed by catalase treatment. Collectively, these data demonstrate that Mb decreases breast cancer cell migration, and this effect is due to heme-mediated oxidant production rather than fatty acid binding. The implication of these results will be discussed in the context of therapeutic strategies to modulate oxidant production and Mb in tumors. Highlights: Myoglobin (Mb) expression in MDA-MB-231 breast cancer cells slows migration.Mb expression decreases mitochondrial respiration and fatty acid oxidation.Mb-dependent fatty acid binding does not regulate cell migration or respiration.Mb-dependent oxidant generation decreases mitochondrial metabolism and migration.Mb-derived oxidants dysregulate migratory gene expression.

Microglial P2Y6 calcium signaling promotes phagocytosis and shapes neuroimmune responses in epileptogenesis.

Microglial calcium signaling is rare in a baseline state but strongly engaged during early epilepsy development. The mechanism(s) governing microglial calcium signaling are not known. By developing an in vivo uridine diphosphate (UDP) fluorescent sensor, GRABUDP1.0, we discovered that UDP release is a conserved response to seizures and excitotoxicity across brain regions. UDP can signal through the microglial-enriched P2Y6 receptor to increase calcium activity during epileptogenesis. P2Y6 calcium activity is associated with lysosome biogenesis and enhanced production of NF-κB-related cytokines. In the hippocampus, knockout of the P2Y6 receptor prevents microglia from fully engulfing neurons. Attenuating microglial calcium signaling through calcium extruder ("CalEx") expression recapitulates multiple features of P2Y6 knockout, including reduced lysosome biogenesis and phagocytic interactions. Ultimately, P2Y6 knockout mice retain more CA3 neurons and better cognitive task performance during epileptogenesis. Our results demonstrate that P2Y6 signaling impacts multiple aspects of myeloid cell immune function during epileptogenesis.

The Impact of Preoperative Weight Loss Timing on Surgical Outcomes in Total Hip Arthroplasty.

BACKGROUND: Elevated body mass index (BMI) increases surgical complications post-total hip arthroplasty (THA). However, the effects of rapid weight loss pre-THA remain unclear. This study evaluated patients who had initial BMIs between 40 and 50, and then achieved a BMI under 35 at various intervals before their THA. Comparisons were made with consistent obese and nonobese groups to understand potential complications. METHODS: Using a national database, we categorized THA patients based on initial BMI and weight loss timing before the surgery. These were contrasted with those maintaining a steady BMI of 20 to 30 or 40 to 50. We monitored outcomes like periprosthetic joint infections (PJI), surgical site infections (SSI), and noninfectious revisions for 2 years postsurgery, incorporating demographic considerations. Statistical analyses utilized Chi-square tests for categorical outcomes and Student's t-tests for continuous variables. RESULTS: Among patients who had a BMI of 45 to 50, weight loss 3 to 9 months presurgery increased PJI risks at 90 days (Odds Ratios [OR]: 2.15 to 5.22, P < .001). However, weight loss a year before the surgery lowered the PJI risk (OR: 0.14 to 0.27, P < .005). Constantly obese patients faced heightened PJI risks 1 to 2 years postsurgery (OR: 1.64 to 1.95, P < .015). Regarding SSI, risks increased with weight loss 3 to 9 months before surgery, but decreased when weight loss occurred a year earlier. In the BMI 40 to 45 group, weight loss 3 to 6 months presurgery showed higher PJI and SSI at 90 days (P < .001), with obese participants consistently at greater risk. CONCLUSIONS: While high BMI poses THA risks, weight loss timing plays a crucial role in postoperative complications. Weight loss closer to the surgery (0 to 9 months) can heighten risks, but shedding weight a year in advance seems beneficial. Conversely, initiating weight loss approximately a year before surgery offers potential protective effects against postoperative issues. This highlights the importance of strategic weight management guidance for patients considering THA, ensuring optimal surgical results and reducing potential adverse outcomes.

Co-Developing Theories of Change for Improved Community-Based Violence Intervention Evaluation.

BACKGROUND: Community-based violence intervention (CVI) programs are considered important strategies for preventing community violence and promoting health and safety. Mixed and inconclusive results from some prior CVI evaluations-and our general lack of understanding about the reasons for such varied findings-may be explained in part by misalignment of program theories of change and evaluation measures. Further, most prior evaluations have focused solely on deficit-based outcomes; this narrow focus is inconsistent with the premise of CVI and may fail to capture improvements in health and wellbeing that are on the hypothesized pathway from intervention to violence reduction. METHODS: This paper describes the process and results of co-developing a theory of change for community-based youth firearm violence intervention and prevention programs in Washington state through a community-researcher partnership. We followed a multi-step iterative process, involving 1) CVI program documentation review, 2) individual meetings, and 3) a day-long workshop. RESULTS: The theory of change included 6 key domains: 1) root causes, 2) promotive factors, 3) activities, 4) inter-mediate outcomes, 5) longer-term outcomes, and 6) multi-level context (youth/family, staff/organizational, community, and societal). Root causes were social and structural drivers of community violence. Promotive factors were assets and resources among the community, youth/their families, and community organizations that promote health and safety. Activities were supports and services the program provided to youth and their families, staff, and potentially the broader community. Inter-mediate and longer-term outcomes were the changes among youth, their families, staff, and the community that resulted from program activities. Inter-mediate outcomes may be felt within 6 months to 1 year and longer-term outcomes may be felt after 1-2 years and beyond. CONCLUSIONS: The theory of change we co-developed provides a common lens to conceptualize, compare, and evaluate CVI programs in Washington state and may support more rigorous and equity-centered evaluations.Study type: original investigation. LEVEL OF EVIDENCE: N/A.

Immediate weightbearing is safe after revision total hip arthroplasty for Vancouver B2/B3 periprosthetic femur fractures.

INTRODUCTION: Modular fluted, tapered stems provide a reliable treatment for Vancouver B2/B3 fractures. Historically, these patients had weightbearing restrictions postoperatively. Although full immediate postoperative weightbearing may provide benefits in this patient population, stem subsidence is a concern. QUESTIONS/PURPOSES: The objective of this study was to investigate the effect of post-operative weight-bearing status on stem subsidence in patients treated with modular tapered stems for Vancouver B2 and B3 periprosthetic fractures. We sought to answer two questions: (1) Does full immediate postoperative weightbearing after revision total hip arthroplasty for periprosthetic femur fracture lead to increased stem subsidence compared to protected weightbearing? (2) Is there a mortality difference between these two groups of patients with different weightbearing restrictions? METHODS: From 2009 to 2015 all patients who underwent revision for Vancouver B2/B3 fractures were made non-weightbearing (NWB) for six weeks postoperatively. After 2015, immediate weightbearing as tolerated (WBAT) was allowed postoperatively. We compared stem subsidence between immediate postoperative and final radiographs. Additionally, we performed a Kaplan-Meijer analysis with one-year mortality as an endpoint. RESULTS: The final cohort included forty-seven patients with an average follow-up of 254 days. The average stem subsidence was 1.0 mm (95 % CI, 0.5-1.5 mm) in the NWB cohort and 0.3 mm (95 % CI, 0-0.7 mm) in the WBAT cohort (P = 0.10). In our survivorship analysis, we noted no deaths in the WBAT cohort compared to 17 % mortality in the NWB cohort at the one-year timepoint. CONCLUSION: Allowing patients to weight bear immediately after revision does not increase stem subsidence. Further studies are needed to determine whether early weightbearing provides a mortality benefit.

The Location of Biofilms on Chronic Prosthetic Joint Infections and the Ramifications for Clinical Practice.

Revision surgery is paramount to cure chronic prosthetic joint infections because these infections are associated with biofilms on prosthetics that conventional antibiotics cannot eradicate. However, there is a paucity of research on where in vivo biofilms are located on infected prosthetics. Consequently, the objective of this pilot study was to address this gap in knowledge by staining 5 chronically infected prosthetics, that were removed at the time of revision surgery, with methylene blue. Scanning electron microscopic images were then taken of the methylene blue-stained areas to visualize biofilms. The findings show that all chronically infected prosthetics had biofilms located on the bone-prosthetic interface, yet only 2 had biofilms also located on the prosthetic interface exposed to synovial fluid. Subsequently, this pilot study provides a pathophysiological understanding of why the current treatment paradigm for chronic periprosthetic joint infection requires a revision surgery and not debridement and an implant retention surgery.

Vocal Health Assessment of Professional Performers Returning to the Stage After the COVID-19 Pandemic Shutdown.

OBJECTIVES/HYPOTHESIS: This study assessed the vocal health of performers returning to full-time performance after the COVID-19 pandemic shutdown and investigated how differences in voice usage, exposure to voice care professionals, and vocal pathology before and during the pandemic contributed to variability in self-perceived and instrumental vocal outcome measures. STUDY DESIGN: This was a prospective, case-control observational study conducted at a single outpatient site. METHODS: Twenty-two patients, 11 cases and 11 controls, were enrolled for the study. All participants were full-time singing professionals prior to the COVID-19 pandemic. Cases were recruited from patients presenting to a tertiary care voice center for vocal or pharyngeal complaints. Controls were healthy volunteers recruited from the general population of professional singers in the surrounding metropolitan area. All participants provided responses to the Voice Handicap Index-10, Evaluation of Ability to Sing Easily, and Laryngopharyngeal Measure of Perceived Sensation validated questionnaires as well as a study survey with questions regarding vocal use and history prior to and during the pandemic. All participants underwent instrumental acoustic and videostroboscopic voice evaluations. RESULTS: Cases had poorer outcome measures overall and were more likely to report their voices were worse at study enrollment when compared to their prepandemic perception (P = 0.027). Cases tended to be older and less likely to have pursued alternative employment during the pandemic that involved increased speaking voice use (27% vs 55%), but these differences were not statistically significant. CONCLUSIONS: There was a variable response among performers to the prolonged hiatus from performing during the COVID-19 pandemic. Those with poorer outcomes tended to be older and may have used their voice less during the pandemic. These findings are consistent with detraining periods in the exercise physiology literature and support the construct of treating vocal performers as vocal athletes.

Outcomes of adding cognitive behavioral therapy to medication-assisted treatment for opioid use disorder.

BACKGROUND: With increasing rates of opioid overdose deaths throughout the United States, there is an urgent need to implement interventions to mitigate this trend. Psychosocial interventions are reported to improve retention rates in rehabilitation centers with medication-assisted treatment (MAT) programs for opioid use. LOCAL PROBLEM: In 2020, 14% (187 of 1,309) of opioid overdose deaths in Georgia were in Dougherty County where an intensive outpatient MAT program had historically used twice weekly group therapy plus individual cognitive behavioral therapy (CBT) with an inconsistent duration and frequency. METHOD: Using existing clinical data, a quality-improvement project was designed and implemented to determine whether 60 min of CBT every other week, in addition to weekly group therapy, and prescription medication would result in higher opioid use disorder treatment retention rates. INTERVENTION: A 6-month data analysis of monthly MAT reports compared program retention rates from the 3 months before to 3 months after the policy change. RESULTS: The retention rate significantly increased from 8% to 56% (χ 2 = 8.93, p = .01) following the policy change, adding consistent (98%) individual CBT every other week. CONCLUSIONS: Implementing a policy with a consistent 60 min of individual CBT every other week in addition to the group counseling twice a week and the prescribed medication was associated with an increased retention rate among patients engaged in MAT for opioid use.

The stability of Staphylococcal bacteriophage in presence of local vancomycin concentrations used in clinical practice.

PURPOSE: To evaluate the stability of a clinically used Staphylococcal bacteriophage with doses of vancomycin that are encountered with local administration of vancomycin for musculoskeletal infections. METHODS: A Staphylococcal bacteriophage was evaluated for stability in different pH ranges. Then that same bacteriophage was evaluated for stability with different concentrations of vancomycin and with vancomycin biodegradable antibiotic beads. RESULTS: The bacteriophage had stability within a pH range of 4-10. There was a statistically significant (P < 0.05) decrease in the amount of bacteriophage over 24 h for vancomycin concentrations of 10 mg/mL and 100 mg/mL compared to lower vancomycin concentrations (1 mg/mL, 0.1 mg/mL and normal saline). However, no statistically significant decrease in the amount of bacteriophage was seen with biodegradable vancomycin beads over 24 h. CONCLUSION: These findings have important clinical ramifications in that they show local administration of bacteriophages with concomitant local vancomycin powder therapy should be avoided. Moreover, these findings should spearhead further research into bacteriophage stability in in vivo environments.

An in vivo platform to identify pathogenic loci.

Rare genetic disease discovery efforts typically lead to the identification of new disease genes. PreMIER ( Pre cision M edicine Integrated E xperimental R esources) is a collaborative platform designed to facilitate functional evaluation of human genetic variants in model systems, and to date the PreMIER Consortium has evaluated over 50 variants in patients with genetic disorders. To understand if Drosophila could be used to identify pathogenic disease loci as part of the PreMIER Consortium, we used tissue-specific gene knockdown in the fly as a proof of principle experiment. Tissue-specific knockdown of seven conserved disease genes caused significant changes in viability, longevity, behavior, motor function, and neuronal survival arguing a set of defined assays can be used to determine if a gene of uncertain significance (GUS) regulates specific physiological processes. This study highlights the utility of a tissue-specific knockdown platform in Drosophila to characterize GUS, which may provide the first genephenotype correlations for patients with idiopathic genetic disorders.

Association of COVID-19 Vaccination Rates and Facility Characteristics on COVID-19 Cases, Hospitalizations, and Deaths in US Nursing Homes.

OBJECTIVES: Nursing home residents have been disproportionately affected by the COVID-19 pandemic. Despite recognition as a priority group for receipt of the COVID-19 vaccine, vaccine uptake and COVID-19 cases, hospitalizations, and deaths in nursing home facilities were variable across nursing homes. This study has 2 objectives: (1) to describe nursing facility characteristics associated with higher vs lower vaccination rates and (2) to estimate facility characteristics associated with COVID-19 cases, hospitalizations, and deaths, stratified by vaccination rate. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Facility-level data from 12,811 US nursing home facilities. METHODS: Using the CMS's Nursing Home COVID-19 Public File, we analyzed nursing home COVID-19 vaccination rates and outcomes from June 13, 2021, to September 19, 2021. We performed multivariable logistic regressions and identified facility characteristics associated with increased vaccination uptake and COVID-19 outcomes. RESULTS: Nursing homes with average vaccination rates ≤80% experienced higher total average COVID-19 cases, hospitalizations, and deaths compared to facilities with >80% average vaccination rates during the Delta surge. Moreover, facility factors, such as higher average age of residents, proportion of non-white residents, nurse staffing hours, and occupancy rates, were variably associated with increased risk of COVID-19 outcomes. CONCLUSIONS AND IMPLICATIONS: Facilities with higher resident vaccination rates experienced lower average COVID-19 cases, hospitalizations, and deaths in US nursing homes. Access to vaccines may play a role in mitigating harm associated with infectious diseases. Additionally, facility factors associated with increased adverse outcomes were variably associated with increased odds of COVID-19 outcomes, often, irrespective of vaccination level. As the COVID-19 pandemic continues to evolve and as the possibility of other infectious disease variants emerge, this research provides insight into facility factors, including vaccine uptake, that may mitigate adverse outcomes.

Discrete class I molecules on brain endothelium differentially regulate neuropathology in experimental cerebral malaria.

Cerebral malaria is the deadliest complication that can arise from Plasmodium infection. CD8 T-cell engagement of brain vasculature is a putative mechanism of neuropathology in cerebral malaria. To define contributions of brain endothelial cell major histocompatibility complex (MHC) class I antigen-presentation to CD8 T cells in establishing cerebral malaria pathology, we developed novel H-2Kb LoxP and H-2Db LoxP mice crossed with Cdh5-Cre mice to achieve targeted deletion of discrete class I molecules, specifically from brain endothelium. This strategy allowed us to avoid off-target effects on iron homeostasis and class I-like molecules, which are known to perturb Plasmodium infection. This is the first endothelial-specific ablation of individual class-I molecules enabling us to interrogate these molecular interactions. In these studies, we interrogated human and mouse transcriptomics data to compare antigen presentation capacity during cerebral malaria. Using the Plasmodium berghei ANKA model of experimental cerebral malaria (ECM), we observed that H-2Kb and H-2Db class I molecules regulate distinct patterns of disease onset, CD8 T-cell infiltration, targeted cell death and regional blood-brain barrier disruption. Strikingly, ablation of either molecule from brain endothelial cells resulted in reduced CD8 T-cell activation, attenuated T-cell interaction with brain vasculature, lessened targeted cell death, preserved blood-brain barrier integrity and prevention of ECM and the death of the animal. We were able to show that these events were brain-specific through the use of parabiosis and created the novel technique of dual small animal MRI to simultaneously scan conjoined parabionts during infection. These data demonstrate that interactions of CD8 T cells with discrete MHC class I molecules on brain endothelium differentially regulate development of ECM neuropathology. Therefore, targeting MHC class I interactions therapeutically may hold potential for treatment of cases of severe malaria.

TREM2 mediates MHCII-associated CD4+ T cell response against gliomas.

BACKGROUND: Myeloid cells comprise up to 50% of the total tumor mass in glioblastoma (GBM) and have been implicated in promoting tumor progression and immunosuppression. Modulating the response of myeloid cells to the tumor has emerged as a promising new approach for cancer treatment. In this regard, we focus on the Triggering Receptor Expressed on Myeloid cells 2 (TREM2), which has recently emerged as a novel immune modulator in peripheral tumors. METHODS: We studied the TREM2 expression profile in various patient tumor samples and conducted single-cell transcriptomic analysis in both glioblastoma patients and the GL261 mouse glioma model. We utilized multiple mouse glioma models and employed state-of-the-art techniques such as in vivo two-photon imaging, spectrum flow cytometry, and in vitro co-culture assays to study TREM2 function in myeloid cell-mediated phagocytosis of tumor cells, antigen presentation, and response of CD4+ T cells within the tumor hemispheres. RESULTS: Our research revealed significantly elevated levels of TREM2 expression in brain tumors compared to other types of tumors in patients. TREM2 was predominantly localized in tumor-associated myeloid cells and was highly expressed in nearly all microglia, as well as various subtypes of macrophages. Surprisingly, in pre-clinical glioma models, TREM2 deficiency did not confer a beneficial effect; instead, it accelerated glioma progression. Through detailed investigations, we determined that TREM2 deficiency impaired the ability of tumor-myeloid cells to phagocytose tumor cells and led to reduced expression of MHCII. This deficiency further significantly decreased the presence of CD4+ T cells within the tumor hemispheres. CONCLUSIONS: Our study unveiled a previously unrecognized protective role of tumor-myeloid TREM2. Specifically, we found TREM2 enhance the phagocytosis of tumor cells and promote an immune response by facilitating MHCII-associated CD4+ T cell responses against gliomas.

Spectral flow cytometry identifies distinct nonneoplastic plasma extracellular vesicle phenotype in glioblastoma patients.

Background: Glioblastoma (GBM) is the most common malignant brain tumor and has a poor prognosis. Imaging findings at diagnosis and in response to treatment are nonspecific. Developing noninvasive assays to augment imaging would be helpful. Plasma extracellular vesicles (EVs) are a promising biomarker source for this. Here, we develop spectral flow cytometry techniques that demonstrate differences in bulk plasma EV phenotype between GBM patients and normal donors that could serve as the basis of a liquid biopsy. Methods: Plasma EVs were stained for EV-associated tetraspanins (CD9/CD63/CD81), markers indicating cell of origin (CD11b/CD31/CD41a/CD45), and actin/phalloidin (to exclude cell debris). EVs were analyzed using spectral flow cytometry. Multiparametric analysis using t-distributed stochastic neighbor embedding (t-SNE) and self-organizing maps on flow cytometry data (FlowSOM) was performed comparing GBM and normal donor (ND) plasma EVs. Results: Size exclusion chromatography plus spectral-based flow cytometer threshold settings enriched plasma EVs while minimizing background noise. GBM patients had increased CD9+, CD63+, CD81+, and myeloid-derived (CD11b+) EVs. Multiparametric analysis demonstrated distinct surface marker expression profiles in GBM plasma EVs compared to ND EVs. Fifteen plasma EV sub-populations differing in size and surface marker expression were identified, six enriched in GBM patients and two in normal donors. Conclusions: Multiparametric analysis demonstrates that GBM patients have a distinct nonneoplastic plasma EV phenotype compared to ND. This simple rapid analysis can be performed without purifying tumor EVs and may serve as the basis of a liquid biopsy.

Rapid Implementation of Teletherapy for Voice Disorders: Challenges and Opportunities for Speech-Language Pathologists.

INTRODUCTION: The COVID-19 pandemic necessitated a rapid restructuring of the clinical management of voice and upper airway disorders by speech-language pathologists (SLPs). As in-person therapy sessions were suspended, voice-specialized SLPs across healthcare settings shifted to online teletherapy. In this survey study, we queried voice therapists on their experiences with and opinions regarding the adoption of teletherapy into routine clinical practice. METHODS: Voice-specialized SLPs were recruited nationwide to complete an online survey which included questions about the usability of software and hardware, patient management, the effectiveness of therapy, overall satisfaction, and suggestions for improvement. RESULTS: 48 participants completed the survey. The majority of respondents reported frequent technical difficulties and poor access to or understanding of appropriate equipment. Overall, participants endorsed better patient access, attendance, and compliance, as well as increased scheduling flexibility. While 95% of the respondents stated they would recommend teletherapy to another SLP, only 20% supported a shift to exclusively virtual sessions. Forty percent of respondents endorsed a hybrid model consisting of initial in-person sessions followed by virtual ones. DISCUSSION: Incorporating teletherapy into clinical voice practice has, for the most part, followed Carl May's normalization process theory framework, in that clinicians have invested understanding, training, time and effort, and appraisal into its implementation. However, the unusually rapid pace of change necessitated by the pandemic has presented its own set of challenges. Given the inherent conveniences of virtual therapy, the online modality is likely here to stay. It is critical that we understand the facilitators and barriers to its successful adoption.