Search

PurposeTo assess the safety and efficacy of the third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor osimertinib as neoadjuvant therapy in patients with surgically resectable stage I-IIIA EGFR-mutated non-small cell lung cancer (NSCLC).Patients and methodsThis was a multi-institutional phase II trial of neoadjuvant osimertinib for patients with surgically resectable stage I-IIIA (American Joint Committee on Cancer [AJCC] V7) EGFR-mutated (L858R or exon 19 deletion) NSCLC (ClinicalTrials.gov identifier: NCT03433469). Patients received osimertinib 80 mg orally once daily for up to two 28-day cycles before surgical resection. The primary end point was major pathological response (MPR) rate. Secondary safety and efficacy end points were also assessed. Exploratory end points included pretreatment and post-treatment tumor mutation profiling.ResultsA total of 27 patients were enrolled and treated with neoadjuvant osimertinib for a median 56 days before surgical resection. Twenty-four (89%) patients underwent subsequent surgery; three (11%) patients were converted to definitive chemoradiotherapy. The MPR rate was 14.8% (95% CI, 4.2 to 33.7). No pathological complete responses were observed. The ORR was 52%, and the median DFS was 40.9 months. One treatment-related serious adverse event (AE) occurred (3.7%). No patients were unable to undergo surgical resection or had surgery delayed because of an AE. The most common co-occurring tumor genomic alterations were in TP53 (42%) and RBM10 (21%).ConclusionTreatment with neoadjuvant osimertinib in surgically resectable (stage IA-IIIA, AJCC V7) EGFR-mutated NSCLC did not meet its primary end point for MPR rate. However, neoadjuvant osimertinib did not lead to unanticipated AEs, surgical delays, nor result in a significant unresectability rate.

BACKGROUND: Cardiac arrest is a common and devastating emergency of both the heart and brain. More than 380,000 patients suffer out-of-hospital cardiac arrest annually in the USA. Induced cooling of comatose patients markedly improved neurological and functional outcomes in pivotal randomized clinical trials, but the optimal duration of therapeutic hypothermia has not yet been established. METHODS: This study is a multi-center randomized, response-adaptive, duration (dose) finding, comparative effectiveness clinical trial with blinded outcome assessment. We investigate two populations of adult comatose survivors of cardiac arrest to ascertain the shortest duration of cooling that provides the maximum treatment effect. The design is based on a statistical model of response as defined by the primary endpoint, a weighted 90-day mRS (modified Rankin Scale, a measure of neurologic disability), across the treatment arms. Subjects will initially be equally randomized between 12, 24, and 48 h of therapeutic cooling. After the first 200 subjects have been randomized, additional treatment arms between 12 and 48 h will be opened and patients will be allocated, within each initial cardiac rhythm type (shockable or non-shockable), by response adaptive randomization. As the trial continues, shorter and longer duration arms may be opened. A maximum sample size of 1800 subjects is proposed. Secondary objectives are to characterize: the overall safety and adverse events associated with duration of cooling, the effect on neuropsychological outcomes, and the effect on patient-reported quality of life measures. DISCUSSION: In vitro and in vivo studies have shown the neuroprotective effects of therapeutic hypothermia for cardiac arrest. We hypothesize that longer durations of cooling may improve either the proportion of patients that attain a good neurological recovery or may result in better recovery among the proportion already categorized as having a good outcome. If the treatment effect of cooling is increasing across duration, for at least some set of durations, then this provides evidence of the efficacy of cooling itself versus normothermia, even in the absence of a normothermia control arm, confirming previous RCTs for OHCA survivors of shockable rhythms and provides the first prospective controlled evidence of efficacy in those without initial shockable rhythms. TRIAL REGISTRATION: ClinicalTrials.gov NCT04217551. Registered on 30 December 2019.

BACKGROUND: Patients with telomere biology disorders (TBD) develop hepatic disease, including hepatitis, cirrhosis, and hepatopulmonary syndrome. No specific treatment exists for TBD-related liver disease, and the role of liver transplantation (LT) remains controversial. Our study objectives were to describe the clinical characteristics, management, and outcomes in patients with TBD-related liver disease, and their LT outcomes. METHODS: Data from 83 patients with TBD-associated liver disease were obtained from 17 participating centers in the Clinical Care Consortium of Telomere-Associated Ailments and by self-report for our retrospective, multicenter, international cohort study. RESULTS: Group A (Advanced) included 40 patients with advanced liver disease. Of these, 20 underwent LT (Group AT). Group M (Mild) included 43 patients not warranting LT evaluation, none of whom were felt to be medically unfit for liver transplantation. Supplemental oxygen requirement, pulmonary arteriovenous malformation, hepatopulmonary syndrome, and higher bilirubin and international normalized ratio values were associated with Group A. Other demographics, clinical manifestations, and laboratory findings were similar between groups. Six group A patients were declined for LT; 3 died on the waitlist. Median follow-up post-LT was 2.9 years (range 0.6-13.2 y). One-year survival post-LT was 73%. Median survival post-LT has not been reached. Group AT patients had improved survival by age compared to all nontransplant patients (log-rank test p = 0.02). Of 14 patients with pretransplant hypoxemia, 8 (57%) had improved oxygenation after transplant. CONCLUSIONS: LT recipients with TBD do not exhibit excessive posttransplant mortality, and LT improved respiratory status in 57%. A TBD diagnosis should not exclude LT consideration.

Teaching statistics to undergraduate business students is an enduring challenge, often due to student apprehension and low understanding of relevance. The Data to Decision Project is an approach designed to address this challenge. At the onset of an introductory statistics course, fifty-two students received instruction on the Define, Collect, Organize, Visualize and Analyze (DCOVA) framework to integrate data with business-related decision-making. Concurrent with this instruction, students selected and completed individual projects, using the DCOVA framework to explore their individual decisions. Quantitative and qualitative methods indicated that this approach positively impacted the students' ability to apply statistics, as well as their attitudes regarding their statistics abilities.

Abstract Background Cardiac arrest is a common and devastating emergency of both the heart and brain. More than 380,000 patients suffer out-of-hospital cardiac arrest annually in the USA. Induced cooling of comatose patients markedly improved neurological and functional outcomes in pivotal randomized clinical trials, but the optimal duration of therapeutic hypothermia has not yet been established. Methods This study is a multi-center randomized, response-adaptive, duration (dose) finding, comparative effectiveness clinical trial with blinded outcome assessment. We investigate two populations of adult comatose survivors of cardiac arrest to ascertain the shortest duration of cooling that provides the maximum treatment effect. The design is based on a statistical model of response as defined by the primary endpoint, a weighted 90-day mRS (modified Rankin Scale, a measure of neurologic disability), across the treatment arms. Subjects will initially be equally randomized between 12, 24, and 48 h of therapeutic cooling. After the first 200 subjects have been randomized, additional treatment arms between 12 and 48 h will be opened and patients will be allocated, within each initial cardiac rhythm type (shockable or non-shockable), by response adaptive randomization. As the trial continues, shorter and longer duration arms may be opened. A maximum sample size of 1800 subjects is proposed. Secondary objectives are to characterize: the overall safety and adverse events associated with duration of cooling, the effect on neuropsychological outcomes, and the effect on patient-reported quality of life measures. Discussion In vitro and in vivo studies have shown the neuroprotective effects of therapeutic hypothermia for cardiac arrest. We hypothesize that longer durations of cooling may improve either the proportion of patients that attain a good neurological recovery or may result in better recovery among the proportion already categorized as having a good outcome. If the treatment effect of cooling is increasing across duration, for at least some set of durations, then this provides evidence of the efficacy of cooling itself versus normothermia, even in the absence of a normothermia control arm, confirming previous RCTs for OHCA survivors of shockable rhythms and provides the first prospective controlled evidence of efficacy in those without initial shockable rhythms. Trial registration ClinicalTrials.gov NCT04217551. Registered on 30 December 2019.

Abstract Backgrounds Team leadership skills of physicians working in high-performing medical teams are directly related to outcome. It is currently unclear how these skills can best be developed. Therefore, in this multi-national cross-sectional prospective study, we explored the development of these skills in relation to physician-, organization- and training characteristics of Helicopter Emergency Medicine Service (HEMS) physicians from services in Europe, the United States of America and Australia. Methods Physicians were asked to complete a survey regarding their HEMS service, training, and background as well as a full Leader Behavior Description Questionnaire (LBDQ). Primary outcomes were the 12 leadership subdomain scores as described in the LBDQ. Secondary outcome measures were the association of LBDQ subdomain scores with specific physician-, organization- or training characteristics and self-reported ways to improve leadership skills in HEMS physicians. Results In total, 120 HEMS physicians completed the questionnaire. Overall, leadership LBDQ subdomain scores were high (10 out of 12 subdomains exceeded 70% of the maximum score). Whereas physician characteristics such as experience or base-specialty were unrelated to leadership qualities, both organization- and training characteristics were important determinants of leadership skill development. Attention to leadership skills during service induction, ongoing leadership training, having standards in place to ensure (regular) scenario training and holding structured mission debriefs each correlated with multiple LBDQ subdomain scores. Conclusions Ongoing training of leadership skills should be stimulated and facilitated by organizations as it contributes to higher levels of proficiency, which may translate into a positive effect on patient outcomes. Trial registration Not applicable.

Background: Exposure therapy ("exposure") for youth anxiety is highly underutilized in clinical practice. Asynchronous, online implementation strategies such as online toolkits hold promise as pragmatic approaches for extending the sustainability of evidence-based interventions, but their long-term usage, perceived utility, and impact are rarely studied. Objective: This study presents three-year preliminary implementation outcomes for a free, online toolkit to support exposure therapy use with youth: the Resource for Exposure for Anxiety Disordered Youth (READY; www.bravepracticeforkids.com). Implementation outcomes of interest included READY usage statistics, adoption, perceived utility, and clinician exposure use. Methods: Web analytics characterized usage patterns. A survey of READY users (N = 49; M age = 34.2, 82.9% female, 71% White) assessed adoption, perceived utility, clinician exposure use, and persistent barriers to exposure use. Results: In its first three years, READY had 13,543 page views across 1,731 unique users; 442 (25.6%) registered as a site user to access specialized content. Survey data suggested variability in usage and perceived utility across toolkit components. Qualitative analyses highlighted persistent exposure barriers that pointed to potential READY refinements. Conclusions: Overall, READY has been accessed by hundreds of clinicians, but its impact was limited by low return to the site. This study highlights strengths and limitations of standalone online implementation supports and identifies additional steps needed to optimally support clinicians to deliver exposure to youth in need.

IntroductionMilitary Veterans have an increased risk of suicide compared to the general population, but less is known about changes in risk with the onset of the COVID-19 pandemic, or whether any changes have been moderated by psychiatric or demographic factors. The primary objective was to test the hypothesis that the likelihood of suicide attempt or death by suicide was stable during the first year of the pandemic versus the preceding year for the full sample. A second objective was to test the hypothesis that, in contrast, risk increased for Veteran subgroups characterized by traditional risk factors (e.g., psychiatric diagnosis).Materials and methodsWe extracted electronic health record data for 771,570 Veterans who received one or more health care visits between March 13, 2019, and March 12, 2021, at eight VA hospitals across the southwestern United States. Primary outcome measures were suicide attempts and deaths by suicide. Predictor variables included psychiatric diagnoses and demographic factors.ResultsMultivariable models indicated that the odds of death by suicide did not change during the first year of the COVID-19 pandemic, while the odds of making a suicide attempt declined. Veterans treated for major depression were at heightened risk for attempting suicide in both years, but the association was smaller during the pandemic than the year prior. In contrast, the relative risk of attempt for Veterans who were never married and Veterans treated for a non-alcohol, non-opioid substance-use disorder increased during the pandemic.Conclusions and relevanceThe findings suggest that the pandemic has not led to an increase in suicidal behavior, which is consistent with other studies, although the degree of decline varied across diagnostic and demographic groups. Further longitudinal research is needed to evaluate whether the prolonged nature of COVID-19 may lead to changes in risk over time.

The DNA damage response (DDR) ensures error-free DNA replication and transcription and is disrupted in numerous diseases. An ongoing challenge is to determine the proteins orchestrating DDR and their organization into complexes, including constitutive interactions and those responding to genomic insult. Here, we use multi-conditional network analysis to systematically map DDR assemblies at multiple scales. Affinity purifications of 21 DDR proteins, with/without genotoxin exposure, are combined with multi-omics data to reveal a hierarchical organization of 605 proteins into 109 assemblies. The map captures canonical repair mechanisms and proposes new DDR-associated proteins extending to stress, transport, and chromatin functions. We find that protein assemblies closely align with genetic dependencies in processing specific genotoxins and that proteins in multiple assemblies typically act in multiple genotoxin responses. Follow-up by DDR functional readouts newly implicates 12 assembly members in double-strand-break repair. The DNA damage response assemblies map is available for interactive visualization and query (ccmi.org/ddram/).

BACKGROUND: Genetic changes that drive the transition from lepidic to invasive cancer development within a radiographic ground glass or semi-solid lung lesion (SSL) are not well understood. Biomarkers to predict the transition to solid, invasive cancer within SSL are needed. METHODS: Patients with surgically resected SSL were identified retrospectively from a surgical database. Clinical characteristics and survival were compared between stage I SSL (n = 65) and solid adenocarcinomas (n = 120) resected during the same time period. Areas of normal lung, in situ lepidic, and invasive solid tumor were microdissected from within the same SSL specimens and next generation sequencing (NGS) and Affymetrix microarray of gene expression were performed. RESULTS: There were more never smokers, Asian patients, and sub-lobar resections among SSL but no difference in 5-year survival between SSL and solid adenocarcinoma. Driver mutations found in both lepidic and solid invasive portion were EGFR (43%), KRAS (21%), and DNMT3A (5%). CEACAM5 was the most upregulated gene found in solid, invasive portions of SSL. Lepidic and invasive solid areas had many similarities in gene expression, however there were some significant differences with the gene SPP1 being a unique biomarker for the invasive component of a SSL. CONCLUSIONS: Common lung cancer driver mutations are present in in situ lepidic as well as invasive solid portions of a SSL, suggesting early development of driver mutations. CEACAM5 and SPP1 emerged as promising biomarkers of invasive potential in semi-solid lesions. Other studies have shown both genes to correlate with poor prognosis in lung cancer and their role in evolution of semi-solid lung lesions warrants further study.

Tissue repair responses in metazoans are highly coordinated by different cell types over space and time. However, comprehensive single-cell-based characterization covering this coordination is lacking. Here, we captured transcriptional states of single cells over space and time during skin wound closure, revealing choreographed gene-expression profiles. We identified shared space-time patterns of cellular and gene program enrichment, which we call multicellular "movements" spanning multiple cell types. We validated some of the discovered space-time movements using large-volume imaging of cleared wounds and demonstrated the value of this analysis to predict "sender" and "receiver" gene programs in macrophages and fibroblasts. Finally, we tested the hypothesis that tumors are like "wounds that never heal" and found conserved wound healing movements in mouse melanoma and colorectal tumor models, as well as human tumor samples, revealing fundamental multicellular units of tissue biology for integrative studies.

This article focuses on the role of cooperating teachers (CTs)/mentors in supporting pre-service teachers in urban middle schools. This article examines stories of ten middle school teachers at Baldwin Middle School, located in a mid-Atlantic urban center, who served as CTs in the Spring of 2016. After comparing the mentors' experiences, four major themes emerged that focus on preparing urban and middle-level pre-service teachers: culturally responsive pedagogy, classroom management, flexibility, and resources. This article describes the qualities of mentorship that are unique to urban middle schools, and how CTs can prepare future educators to effectively teach in this environment.

Long noncoding RNA (lncRNA) genes outnumber protein coding genes in the human genome and the majority remain uncharacterized. A major difficulty in generalizing understanding of lncRNA function is the dearth of gross sequence conservation, both for lncRNAs across species and for lncRNAs that perform similar functions within a species. Machine learning based methods which harness vast amounts of information on RNAs are increasingly used to impute certain biological characteristics. This includes interactions with proteins that are important mediators of RNA function, thus enabling the generation of knowledge in contexts for which experimental data are lacking. Here, we applied a natural language-based machine learning approach that enabled us to identify RNA binding protein interactions in lncRNA transcripts, using only RNA sequence as an input. We found that this predictive method is a powerful approach to infer conserved binding across species as distant as human and opossum, even in the absence of sequence conservation, thus informing on sequence-function relationships for these poorly understood RNAs.

BackgroundCognitive dysfunction is a common problem in multiple sclerosis (MS). Progress toward understanding and treating cognitive dysfunction is thwarted by the limitations of traditional cognitive tests, which demonstrate poor sensitivity and ecological validity. Ambulatory methods of assessing cognitive function in the lived environment may improve the detection of subtle changes in cognitive function and the identification of predictors of cognitive changes and downstream effects of cognitive change on other functional domains. ObjectiveThis paper describes the study design and protocol for the Optimizing Detection and Prediction of Cognitive Function in Multiple Sclerosis (CogDetect-MS) study, a 2-year longitudinal observational study designed to examine short- and long-term changes in cognition, predictors of cognitive change, and effects of cognitive change on social and physical function in MS. MethodsParticipants—ambulatory adults with medically documented MS—are assessed over the course of 2 years on an annual basis (3 assessments: T1, T2, and T3). A comprehensive survey battery, in-laboratory cognitive and physical performance tests, and 14 days of ambulatory data collection are completed at each annual assessment. The 14-day ambulatory data collection includes continuous wrist-worn accelerometry (to measure daytime activity and sleep); ecological momentary assessments (real-time self-report) of somatic symptoms, mood, and contextual factors; and 2 brief, validated cognitive tests, administered by smartphone app 4 times per day. Our aim was to recruit 250 participants. To ensure standard test protocol administration, all examiners passed a rigorous examiner certification process. Planned analyses include (1) nonparametric 2-tailed t tests to compare in-person to ambulatory cognitive test scores; (2) mixed effects models to examine cognitive changes over time; (3) mixed effects multilevel models to evaluate whether ambulatory measures of physical activity, sleep, fatigue, pain, mood, and stress predict changes in objective or subjective measures of cognitive functioning; and (4) mixed effects multilevel models to examine whether ambulatory measures of cognitive functioning predict social and physical functioning over short (within-day) and long (over years) time frames. ResultsThe study was funded in August 2021 and approved by the University of Michigan Medical Institutional Review Board on January 27, 2022. A total of 274 adults with MS (first participant enrolled on May 12, 2022) have been recruited and provided T1 data. Follow-up data collection will continue through March 2026. ConclusionsResults from the CogDetect-MS study will shed new light on the temporal dynamics of cognitive function, somatic and mood symptoms, sleep, physical activity, and physical and social function. These insights have the potential to improve our understanding of changes in cognitive function in MS and enable us to generate new interventions to maintain or improve cognitive function in those with MS. Trial RegistrationClinicalTrials.gov NCT05252195; https://clinicaltrials.gov/study/NCT05252195 International Registered Report Identifier (IRRID)DERR1-10.2196/59876

Abstract Although classically recognized as a neurotransmitter, gamma aminobutyric acid (GABA) has also been identified in colonic tumors. Moreover, the gut microbiome represents another potential source of GABA. Both GABAA and GABAB receptors have been implicated in contributing to the effects of GABA in colorectal cancer, with both pro‐ and anti‐tumorigenic functions identified. However, their subunit composition is often overlooked. Studies to date have not addressed whether the GABA‐producing potential of the microbiome changes over the course of colon tumor development or whether receptor subunit expression patterns are altered in colon cancer. Therefore, we investigated the clusters of orthologous group frequencies of glutamate decarboxylase (GAD) in feces from two murine models of colon cancer and found that the frequency of microbial GAD was significantly decreased early in the tumorigenic process. We also determined that microbial‐derived GABA inhibited proliferation of colon cancer cells in vitro and that this effect of GABA on SW480 cells involved both GABAA and GABAB receptors. GABA also inhibited prostaglandin E2 (PGE2)‐induced proliferation and interleukin‐6 (IL‐6) expression in these cells. Gene expression correlations were assessed using the “Cancer Exploration” suite of the TIMER2.0 web tool and identified that GABA receptor subunits were differentially expressed in human colon cancer. Moreover, GABAA receptor subunits were predominantly positively associated with PGE2 synthase, cyclooxygenase‐2 and IL‐6. Collectively, these data demonstrate decreased potential of the microbiome to produce GABA during tumorigenesis, a novel anti‐tumorigenic pathway for GABA, and that GABA receptor subunit expression adds a further layer of complexity to GABAergic signaling in colon cancer.

Ancestral SARS coronavirus-2 (SARS-CoV-2) and variants of concern (VOC) caused a global pandemic with a spectrum of disease severity. The mechanistic explaining variations related to airway epithelium are relatively understudied. Here, we biobanked airway organoids (AO) by preserving stem cell function. We optimized viral infection with H1N1/PR8 and comprehensively characterized epithelial responses to SARS-CoV-2 infection in phenotypically stable AO from 20 different subjects. We discovered Tetraspanin-8 (TSPAN8) as a facilitator of SARS-CoV-2 infection. TSPAN8 facilitates SARS-CoV-2 infection rates independently of ACE2-Spike interaction. In head-to-head comparisons with Ancestral SARS-CoV-2, Delta and Omicron VOC displayed lower overall infection rates of AO but triggered changes in epithelial response. All variants shared highest tropism for ciliated and goblet cells. TSPAN8-blocking antibodies diminish SARS-CoV-2 infection and may spur novel avenues for COVID-19 therapy.

Background: Suicide among adolescents has long been linked to symptoms of depression. However, limited research has examined the potential buffering effect of hope on the relationship between depression and suicide attempts. Methods: To test the effect of hope on the positive relationship between depression and suicide attempts, we used data (N = 502 adolescents) from youth ages 12-18 collected as part of the 2018 Healthy Youth Survey in the State of Washington. Based on hope theory, we hypothesized a "buffering" form of moderation, with the presence of greater hope weakening the positive relationship between depression and suicide attempts. In other words, with higher hope, adolescents reporting depressive symptoms are less inclined to attempt suicide. Results: Testing the moderating effect of hope via bootstrap resampling (N = 5000), the results indicated adolescents' hope levels indeed buffered the relationship between depressive symptoms and self-reported suicide attempts. To wit, when adolescents' hope was low, there was a significant, robust, and positive relationship between depressive symptoms and suicide attempts (b = 0.2644, 95% CI [0.1604, 0.3683], t = 5.0, p < 0.001). However, when adolescents' hope was high, there was no longer a significant relationship between depressive symptoms and suicide attempts (b = 0.0304, 95% CI [-0.997, 0.1605], t = 0.4590, p = 0.65). Conclusion: The buffering effect of hope was validated in a second, larger sample (n = 9308) of adolescents. This result suggests the potential utility of hope theory-based interventions to assist depressed adolescents reduce their likelihood of suicide.

Abstract Constitutional heterozygous pathogenic variants in genes coding for some components of the Fanconi anemia-BRCA signaling pathway, which repairs DNA interstrand crosslinks, represent risk factors for common cancers, including breast, ovarian, pancreatic and prostate cancer. A high cancer risk is also a main clinical feature in patients with Fanconi anemia (FA), a rare condition characterized by bone marrow failure, endocrine and physical abnormalities. The mainly recessive condition is caused by germline pathogenic variants in one of 21 FA-BRCA pathway genes. Among patients with FA, the highest cancer risks are observed in patients with biallelic pathogenic variants in BRCA2 or PALB2. These patients develop a range of embryonal tumors and leukemia during the first decade of life, however, little is known about specific clinical, genetic and pathologic features or toxicities. Here, we present genetic, clinical, pathological and treatment characteristics observed in an international cohort of eight patients with FA due to biallelic BRCA2 pathogenic variants and medulloblastoma (MB), an embryonal tumor of the cerebellum. Median age at MB diagnosis was 32.5 months (range 7–58 months). All patients with available data had sonic hedgehog-MB. Six patients received chemotherapy and one patient also received proton radiation treatment. No life-threatening toxicities were documented. Prognosis was poor and all patients died shortly after MB diagnosis (median survival time 4.5 months, range 0–21 months) due to MB or other neoplasms. In conclusion, MB in patients with biallelic BRCA2 pathogenic variants is a lethal disease. Future experimental treatments are necessary to help these patients.

Abstract Background A frequent complication of Fontan operations is unilateral diaphragmatic paresis, which leads to hemodynamic deterioration of the Fontan circulation. A potential new therapeutic option is the unilateral diaphragmatic pacemaker. In this study, we investigated the most effective stimulation location for a potential fully implantable system in a porcine model. Methods Five pigs (20.8 ± 0.95 kg) underwent implantation of a customized cuff electrode placed around the right phrenic nerve. A bipolar myocardial pacing electrode was sutured adjacent to the motor point and peripherally at the costophrenic angle (peripheral diaphragmatic muscle). The electrodes were stimulated 30 times per minute with a pulse duration of 200 µs and a stimulation time of 300 ms. Current intensity was the only variable changed during the experiment. Results Effective stimulation occurred at 0.26 ± 0.024 mA at the phrenic nerve and 7 ± 1.22 mA at the motor point, a significant difference in amperage (p = 0.005). Even with a maximum stimulation of 10 mA at the peripheral diaphragm muscle, however, no effective stimulation was observed. Conclusion The phrenic nerve seems to be the best location for direct stimulation by a unilateral thoracic diaphragm pacemaker in terms of the required amperage level in a porcine model.

Shailey Gale Twamley,1– 3 Niclas Gimber,4 Héctor Eduardo Sánchez-Ibarra,1,2 Tobias Christaller,1,2 Victoria Isakzai,1,2 Harald Kratz,5 Ronodeep Mitra,6 Lena Kampen,1– 3 Anke Stach,1,2 Heike Heilmann,7 Berit Söhl-Kielczynski,8 Eno Essien Ebong,6,9,10 Jan Schmoranzer,4 Agnieszka Münster-Wandowski,7,&ast; Antje Ludwig1– 3,&ast; 1Department of Cardiology, Angiology and Intensive Care Medicine, Deutsches Herzzentrum der Charité, Berlin, Germany; 2Department of Cardiology, Angiology and Intensive Care Medicine, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin, Germany; 3DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany; 4Advanced Medical Bioimaging Core Facility (AMBIO), Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; 5Department of Radiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; 6Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 7Institute of Integrative Neuroanatomy, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany; 8Institute for Integrative Neurophysiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany; 9Department of Bioengineering, Northeastern University, Boston, MA, USA; 10Department of Neuroscience, Albert Einstein College of Medicine, New York, NY, USA&ast;These authors contributed equally to this workCorrespondence: Shailey Gale Twamley; Antje Ludwig, Tel +49-30-450-528455 ; +49-30-450-513196, Fax +49-30-450-528922 ; +49-30-450941, Email shailey.twamley@charite.de; antje.ludwig@dhzc-charite.dePurpose: To study whether the absence of laminar shear stress (LSS) enables the uptake of very small superparamagnetic iron oxide nanoparticles (VSOP) in endothelial cells by altering the composition, size, and barrier function of the endothelial surface layer (ESL).Methods and Results: A quantitative particle exclusion assay with living human umbilical endothelial cells using spinning disc confocal microscopy revealed that the dimension of the ESL was reduced in cells cultivated in the absence of LSS. By combining gene expression analysis, flow cytometry, high pressure freezing/freeze substitution immuno-transmission electron microscopy, and confocal laser scanning microscopy, we investigated changes in ESL composition. We found that increased expression of the hyaluronan receptor CD44 by absence of shear stress did not affect the uptake rate of VSOPs. We identified collagen as a previously neglected component of ESL that contributes to its barrier function. Experiments with inhibitor halofuginone and small interfering RNA (siRNA) demonstrated that suppression of collagen expression facilitates VSOP uptake in endothelial cells grown under LSS.Conclusion: The absence of laminar shear stress disturbs the barrier function of the ESL, facilitating membrane accessibility and endocytic uptake of VSOP. Collagen, a previously neglected component of ESL, contributes to its barrier function. Keywords: citrate coated nanoparticles, atherosclerosis, blood flow, endothelial barrier, permeability, internalization

Katarzyna So&lstrok;kiewicz,1 Izabela Kokot,1 Violetta Dymicka-Piekarska,2 Justyna Dorf,2 Ewa Maria Kratz1 1Department of Laboratory Diagnostics, Division of Laboratory Diagnostics, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland; 2Department of Clinical Laboratory Diagnostics, Medical University of Bialystok, Bialystok, PolandCorrespondence: Ewa Maria Kratz; Katarzyna So&lstrok;kiewicz, Email ewa.kratz@umw.edu.pl; katarzyna.solkiewicz@umw.edu.plIntroduction: Immunoglobulin G (IgG) glycosylation affects its effector functions and is essential in many steps of the inflammatory cascade. Therefore, it may be an important parameter for assessing the body’s immune response during the course of COVID-19 (Coronavirus disease 2019).Methods: The N- and O-glycosylation of serum IgG in severe COVID-19 patients (n=87), convalescents (n=50), and healthy subjects (n=65) were examined using a modified lectin-ELISA method with specific biotinylated lectins. The obtained data were analyzed using STATISTICA 13.3PL software.Results: We showed significantly higher expression of Lewisx oligosaccharide structures in severe COVID-19 patients than in the other two groups. Moreover, significantly lower expression of Lewisy sugar structures in IgG glycans was observed in the convalescents when compared with COVID-19 patients and healthy subjects. The lowest expression of highly branched N-glycans in cases of severe COVID-19 indicates that the development of the disease is associated with the presence of typical IgG biantennary N-glycans. The lack of significant differences in the expression of Tn antigen in IgG between studied groups and the significantly lower expression of T antigen in convalescents compared to the patients with severe COVID-19 and healthy subjects indicates a decrease in the content of the T antigen in IgG O-glycans in subjects recovered from COVID-19. Substantially higher reactivities of IgG O-glycans with Jacalin observed in COVID-19 patients and convalescents in comparison to the control group were most probably caused by increased expression of core 3 O-glycans in IgG.Conclusion: Severe COVID-19 is accompanied by the expression in serum IgG of sialylated biantennary and highly branched N-glycans, decorated by fucose of Lewisx and Lewisy structures. The higher reactivity of IgG O-glycans with Jacalin in severe COVID-19 patients and convalescents indicates that the disease development and the recovery process are most probably accompanied by increased expression of the core 3 O-glycans.Keywords: serum IgG, glycosylation, SARS-CoV-2, COVID-19, inflammation