Spatial transcriptomics at the brain-electrode interface in rat motor cortex and the relationship to recording quality.

Study of the foreign body reaction to implanted electrodes in the brain is an important area of research for the future development of neuroprostheses and experimental electrophysiology. After electrode implantation in the brain, microglial activation, reactive astrogliosis, and neuronal cell death create an environment immediately surrounding the electrode that is significantly altered from its homeostatic state. To uncover physiological changes potentially affecting device function and longevity, spatial transcriptomics was implemented to identify changes in gene expression driven by electrode implantation and compare this differential gene expression to traditional metrics of glial reactivity, neuronal loss, and electrophysiological recording quality. For these experiments, rats were chronically implanted with functional Michigan-style microelectrode arrays, from which electrophysiological recordings (multi-unit activity, local field potential) were taken over a six-week time course. Brain tissue cryosections surrounding each electrode were then mounted for spatial transcriptomics processing. The tissue was immunolabeled for neurons and astrocytes, which provided both a spatial reference for spatial transcriptomics and a quantitative measure of glial fibrillary acidic protein (GFAP) and neuronal nuclei (NeuN) immunolabeling surrounding each implant. Results from rat motor cortex within 300µm of the implanted electrodes at 24 hours, 1 week, and 6 weeks post-implantation showed up to 553 significantly differentially expressed (DE) genes between implanted and non-implanted tissue sections. Regression on the significant DE genes identified the 6-7 genes that had the strongest relationship to histological and electrophysiological metrics, revealing potential candidate biomarkers of recording quality and the tissue response to implanted electrodes .

Synthesis, modeling, and biological evaluation of anti-tubulin indole-substituted furanones.

Due to the central role of tubulin in various cellular functions, it is a validated target for anti-cancer therapeutics. However, many of the current tubulin inhibitors are derived from complex natural products and suffer from multidrug resistance, low solubility, toxicity issues, and/or the lack of multi-cancer efficacy. As such, there is a continued need for the discovery and development of new anti-tubulin drugs to enter the pipeline. Herein we report on a group of indole-substituted furanones that were prepared and tested for anti-cancer activity. Molecular docking studies showed positive correlations between favorable binding in the colchicine binding site (CBS) of tubulin and anti-proliferative activity, and the most potent compound was found to inhibit tubulin polymerization. These compounds represent a promising new structural motif in the search for small heterocyclic CBS cancer inhibitors.

Spatiotemporal expression of RNA-seq identified proteins at the electrode interface.

Implantation of electrodes in the brain can be used to record from or stimulate neural tissues to treat neurological disease and injury. However, the tissue response to implanted devices can limit their functional longevity. Recent RNA-seq datasets identify hundreds of genes associated with gliosis, neuronal function, myelination, and cellular metabolism that are spatiotemporally expressed in neural tissues following the insertion of microelectrodes. To validate mRNA as a predictor of protein expression, this study evaluates a sub-set of RNA-seq identified proteins (RSIP) at 24-hours, 1-week, and 6-weeks post-implantation using quantitative immunofluorescence methods. This study found that expression of RSIPs associated with glial activation (Glial fibrillary acidic protein (GFAP), Polypyrimidine tract binding protein-1 (Ptbp1)), neuronal structure (Neurofilament heavy chain (Nefh), Proteolipid protein-1 (Plp1), Myelin Basic Protein (MBP)), and iron metabolism (Transferrin (TF), Ferritin heavy chain-1 (Fth1)) reinforce transcriptional data. This study also provides additional context to the cellular distribution of RSIPs using a MATLAB-based approach to quantify immunofluorescence intensity within specific cell types. Ptbp1, TF, and Fth1 were found to be spatiotemporally distributed within neurons, astrocytes, microglia, and oligodendrocytes at the device interface relative to distal and contralateral tissues. The altered distribution of RSIPs relative to distal tissue is largely localized within 100µm of the device injury, which approaches the functional recording range of implanted electrodes. This study provides evidence that RNA-sequencing can be used to predict protein-level changes in cortical tissues and that RSIPs can be further investigated to identify new biomarkers of the tissue response that influence signal quality. STATEMENT OF SIGNIFICANCE: Microelectrode arrays implanted into the brain are useful tools that can be used to study neuroscience and to treat pathological conditions in a clinical setting. The tissue response to these devices, however, can severely limit their functional longevity. Transcriptomics has deepened the understandings of the tissue response by revealing numerous genes which are differentially expressed following device insertion. This manuscript provides validation for the use of transcriptomics to characterize the tissue response by evaluating a subset of known differentially expressed genes at the protein level around implanted electrodes over time. In additional to validating mRNA-to-protein relationships at the device interface, this study has identified emerging trends in the spatiotemporal distribution of proteins involved with glial activation, neuronal remodeling, and essential iron binding proteins around implanted silicon devices. This study additionally provides a new MATLAB based methodology to quantify protein distribution within discrete cell types at the device interface which may be used as biomarkers for further study or therapeutic intervention in the future.

Spatial Transcriptomics as a Novel Approach to Redefine Electrical Stimulation Safety.

Current standards for safe delivery of electrical stimulation to the central nervous system are based on foundational studies which examined post-mortem tissue for histological signs of damage. This set of observations and the subsequently proposed limits to safe stimulation, termed the "Shannon limits," allow for a simple calculation (using charge per phase and charge density) to determine the intensity of electrical stimulation that can be delivered safely to brain tissue. In the three decades since the Shannon limits were reported, advances in molecular biology have allowed for more nuanced and detailed approaches to be used to expand current understanding of the physiological effects of stimulation. Here, we demonstrate the use of spatial transcriptomics (ST) in an exploratory investigation to assess the biological response to electrical stimulation in the brain. Electrical stimulation was delivered to the rat visual cortex with either acute or chronic electrode implantation procedures. To explore the influence of device type and stimulation parameters, we used carbon fiber ultramicroelectrode arrays (7 µm diameter) and microwire electrode arrays (50 µm diameter) delivering charge and charge density levels selected above and below reported tissue damage thresholds (range: 2-20 nC, 0.1-1 mC/cm2). Spatial transcriptomics was performed using Visium Spatial Gene Expression Slides (10x Genomics, Pleasanton, CA, United States), which enabled simultaneous immunohistochemistry and ST to directly compare traditional histological metrics to transcriptional profiles within each tissue sample. Our data give a first look at unique spatial patterns of gene expression that are related to cellular processes including inflammation, cell cycle progression, and neuronal plasticity. At the acute timepoint, an increase in inflammatory and plasticity related genes was observed surrounding a stimulating electrode compared to a craniotomy control. At the chronic timepoint, an increase in inflammatory and cell cycle progression related genes was observed both in the stimulating vs. non-stimulating microwire electrode comparison and in the stimulating microwire vs. carbon fiber comparison. Using the spatial aspect of this method as well as the within-sample link to traditional metrics of tissue damage, we demonstrate how these data may be analyzed and used to generate new hypotheses and inform safety standards for stimulation in cortex.

Empowering the affected: Informing community-based solutions through interviews with survivors of interpersonal firearm violence-Perspectives of survivors of firearm injuries.

BACKGROUND: Firearm violence remains epidemic in the United States, with interpersonal gun violence leading to significant morbidity and mortality. Interpersonal violence has strong associations with social determinants of health, and community-specific solutions are needed to address root causes. We hypothesized that open-ended interviews with survivors of interpersonal firearm violence would identify themes in individual and community-level factors that contribute to ongoing violence. METHODS: Between July 2017 and November 2019, we performed a mixed-methods study in which qualitative and quantitative data were obtained from survivors of interpersonal firearm violence admitted to our urban level I trauma center. Qualitative data were obtained through semistructured, open-ended interviews with survivors. Quantitative data were obtained via survey responses provided to these same individuals. Qualitative and quantitative data were then used to triangulate and strengthen results. RESULTS: During the study period, 51 survivors were enrolled in the study. The most common cause of firearm violence reported by survivors was increased gang and drug activity (n = 40, 78%). The most common solution expressed was to reduce drug and gang lifestyle by offering jobs and educational opportunities to afflicted communities to improve opportunities (n = 35, 69%). Nearly half of the survivors (n = 23, 45%) believe that firearm violence should be dealt with by the affected community itself, and another group of survivors believe that it should be through partnership between the community and trauma centers (n = 19, 37%). CONCLUSION: Interviews with survivors of firearm violence at our urban level I trauma center suggest that drug and gang lifestyle perpetuate ongoing violence and that this would best be overcome by improving access to quality education and job opportunities. To address endemic firearm violence in their communities, trauma centers should identify opportunities to partner in developing programs that provide improved education, job access, and conflict mediation. LEVEL OF EVIDENCE: Prognostic and epidemiological, level I.

ELTD1, an effective anti-angiogenic target for gliomas: preclinical assessment in mouse GL261 and human G55 xenograft glioma models.

Background: Despite current therapies, glioblastoma is a devastating cancer, and validation of effective biomarkers for it will enable better diagnosis and therapeutic intervention for this disease. We recently discovered a new biomarker for high-grade gliomas, ELTD1 (epidermal growth factor, latrophilin, and 7 transmembrane domain-containing protein 1 on chromosome 1) via bioinformatics, and validated that ELTD1 protein levels are significantly higher in human and rodent gliomas. The focus of this study was to assess the effect on tumor growth of an antibody against ELTD1 in orthotopic, GL261, and G55 xenograft glioma models. Methods: The effect of anti-ELTD1 antibody therapy was assessed by animal survival, MRI measured tumor volumes, MR angiography, MR perfusion imaging, and immunohistochemistry (IHC) characterization of microvessel density in mouse glioma models. Comparative treatments included anti-vascular endothelial growth factor (VEGF) and anti-c-Met antibody therapies, compared with untreated controls. Results: Tumor volume and survival data in this study show that antibodies against ELTD1 inhibit glioma growth just as effectively or even more so compared with other therapeutic targets studied, including anti-VEGF antibody therapy. Untreated GL261 or G55 tumors were found to have significantly higher ELTD1 levels (IHC) compared with contralateral normal brain. The anti-angiogenic effect of ELTD1 antibody therapy was observed in assessment of microvessel density, as well as from MR angiography and perfusion measurements, which indicated that anti-ELTD1 antibody therapy significantly decreased vascularization compared with untreated controls. Conclusions: Either as a single therapy or in conjunction with other therapeutic approaches, anti-ELTD1 antibodies could be a valuable new clinical anti-angiogenic therapeutic for high-grade gliomas.

Incontinent or continent urinary diversion: how to make the right choice.

PURPOSE OF REVIEW: To summarize recently published findings regarding functional and health-related quality of life (HRQOL) outcomes associated with conduit and continent urinary diversion, review the evidence (or lack thereof) supporting one diversion type over another, and discuss important factors that impact how patients should likely be counseled regarding choosing between conduit and continent urinary diversions following bladder removal. RECENT FINDINGS: Functional and HRQOL outcomes have become an important aspect of outcome assessment following urinary diversion. Early research has been limited by the lack of disease-specific instruments and a dearth of reliable, responsive and valid measures. Recently, several disease-specific HRQOL questionnaires have been developed using more robust methods and are in the early phase of outcome assessment. Ultimately, data from these assessments may be used to aid in the decision-making process. However, to date, surveys have not exhibited significant differences when comparing various diversion types, including ileal conduit and orthotopic continent neobladder. A review of the recent literature confirms this finding. Instead of attempting to prove the superiority of one diversion type over another, future studies should endeavor to evaluate the relationship between preoperative health status, diversion choice based on patient preference, and postoperative clinical outcomes. SUMMARY: Although postoperative HRQOL outcomes are an important component of counseling prior to urinary diversion procedures, the decision-making process concerning the appropriate type of diversion involves patient education, participation, and in-depth discussion of patient preferences given the preference-sensitive nature of choosing between a conduit and continent diversion.

The effect of pegylated interferon-alpha2b and ribavirin on posttraumatic stress disorder symptoms.

BACKGROUND: Patients with chronic psychiatric diagnoses have a prevalence of chronic hepatitis C (HCV) approximately 11 times higher than the general American population. Posttraumatic stress disorder (PTSD) is particularly common among HCV patients. OBJECTIVE: The authors describe the effect of treatment with pegylated-interferon-alpha(2b) (IFN) and ribavirin for patients with HCV on their posttraumatic stress disorder (PTSD) symptoms. METHOD: Sixteen patients with HCV and combat-related PTSD were followed for 24 weeks and assessed with self-report measures of PTSD, hostility, and depression. RESULTS: Depression and Resentment scores significantly increased in five patients treated with IFN and ribavirin, but no significant differences were found in PTSD scores when compared with 11 control patients. CONCLUSION: The results suggest that patients with PTSD and HCV can be safely treated with anti-viral therapies when they are given appropriate psychiatric care.

Comparison of in-shoe foot loading patterns on natural grass and synthetic turf.

Synthetic playing surfaces with rubber or sand infill are now used on many athletic fields such as soccer, football and rugby. Although these surfaces may come closer to the mechanical characteristics of a true grass playing surface than the older turf designs, their potential effects on lower extremity biomechanics and related injury rates necessitate further study. The purpose of this study was to examine the effects of two surfaces (natural grass versus turf) on in-shoe foot loading patterns during cutting. Seventeen male football players were tested on a slalom course. An in-shoe pressure distribution measurement insole was used in the right shoe (14 stud, molded cleat) of each athlete. Individual cutting steps were extracted from each slalom trial and peak pressure and relative load calculated in nine distinct plantar regions of the foot. The turf condition had significantly higher peak pressures within the central forefoot (turf: 646.6+/-172.6 kPa, grass: 533.3+/-143.4 kPa, P=0.017) and lesser toes (turf: 429.3+/-200.9 kPa, grass: 348.1+/-119.0 kPa, P=0.043) compared to grass. In contrast, the relative load within the medial forefoot (turf: 27.2+/-5.3%, grass: 30.2+/-6.6%, P=0.031) and lateral midfoot (turf: 3.4+/-1.8%, grass: 4.1+/-2.3%, P=0.029) were higher during the grass condition. No differences between the grass and turf were found in maximal effort sprint times performed prior to the testing trials. This study demonstrates that playing surface significantly affects plantar loading during sport related activities. Further epidemiological investigation is warranted to determine the effects of playing surfaces on sport specific injury mechanisms.

The temporal stability of cluster and switch scores using a modified COWAT procedure.

This study examined the impact of instructional changes on the temporal stability of cluster and switch scores for the Controlled Oral Word Association Test [COWAT; Benton, A. L., Hamsher, K., & Sivan, A. B. (1994). Multilingual Aphasia Examination (3rd ed.). Iowa City, IA: AJA Associates]. Healthy undergraduates were assigned randomly into experimental (N = 60) and control (N = 60) groups. Experimental group participants were administered three letters as customary, then informed about clustering strategies prior to completing three additional letters. Control group participants received the original instructions only for all six letters. All participants were examined on two separate occasions. The mean inter-assessment interval was 38.6 days (ranging from 29 to 47 days). Stability coefficients for cluster and switch scores on the last set of letters differed significantly between groups, as higher coefficients were observed for the experimental group. In contrast, stability coefficients for the total words produced and mean cluster size did not differ between groups. Although the temporal stability improved, the resulting coefficients were modest (e.g., r(icc) = .76 for clusters; r(icc) = .79 for switches). We present implications of these findings and considerations for future research.