Education Research: Burnout and Perception of Value in a Cross-Section of Neurology Residency Program Directors.

Background and Objectives: There are no dedicated studies specifically assessing burnout in neurology residency program directors (PDs). A study of residency and fellowship directors across specialties found neurology residency PDs had the highest work-related Copenhagen Burnout Inventory (CBI) score, which may reflect high-level burnout in neurology in general. Indeed, the American Academy of Neurology Burnout Task Force reported burnout in 60% of neurologists. The aims of this study are to determine the level of burnout in adult and pediatric neurology residency PDs, and to determine whether perception of value is related to burnout. Methods: In an IRB-approved study, 184 neurology residency PDs were emailed an anonymous survey consisting of the full CBI, demographic information, and 2 items addressing perception of value in the PD role: "I feel valued by my department in my educational role," to which the participant could respond "strongly disagree, disagree, agree, or strongly agree," and "satisfaction with current percent effort for the educational role," to which the participant could respond "very dissatisfied, dissatisfied, satisfied, or very satisfied." Data were analyzed through analysis of variance and ordinal logistic regression. Results: A total of 85 PDs (46%) responded to the survey. The average ± SEM personal, work-related, and patient-related CBI scores were 41.8 ± 2.2, 39.7 ± 2.2, and 32.4 ± 2.2, respectively. Higher personal and work-related CBI scores were associated with less positive perception of value (proportional odds ratio 1.03, 95% CI 1.01-1.06, p = 0.004 and proportional odds ratio 1.04; 95% CI 1.01-1.06, p = 0.003, respectively). Higher personal and work-related CBI scores were also associated with greater dissatisfaction with percent effort granted for the PD role. Level of burnout did not differ between adult and pediatric PDs. Burnout was not related to sex, years in practice, years as PD, academic rank, or percentage effort granted for the PD role. Discussion: Despite working in a field associated with high burnout, neurology residency PDs were found to have lower-level burnout than previously reported. Ninety-four percent of the PDs reported feeling valued in their role which was associated with lower-level personal and work-related burnout and may represent a key target for reflection and burnout intervention in the future.

Pancreatic cancer tumor organoids exhibit subtype-specific differences in metabolic profiles.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease characterized by complex metabolic rewiring that enables growth in changing nutrient availability and oxygen conditions. Transcriptome-based prognostic PDAC tumor subtypes, known as 'basal-like' and 'classical' subtypes are associated with differences in metabolic gene expression including genes involved in glycolysis. Tumor subtype-specific metabolism phenotypes may provide new targets for treatment development in PDAC, but their functional relevance has not been fully elucidated. We aimed to investigate differences in metabolic profiles and transcriptomes in tumor models derived from patients with basal-like and classical tumors. METHODS: Patient-derived organoids (PDOs) were established from tumor biopsies collected from patients with metastatic PDAC, including three PDOs from basal-like and five PDOs from classical tumors. Metabolic analyses included assessment of differences in metabolic activity using Seahorse Glycolysis and Mito Stress tests and 13C-glucose metabolites tracing analysis. In order to investigate the influence of mitochondrial pyruvate transport on metabolic differences, PDOs were treated with the mitochondrial pyruvate carrier 1 (MPC1) inhibitor UK-5099. Prognostic relevance of MPC1 was determined using a tumor tissue microarray (TMA) in resectable, and proteomics profiling in metastatic PDAC datasets. Whole genome and transcriptome sequencing, differential gene expression and gene set enrichment analyses were performed in PDOs. RESULTS: Metastatic PDAC PDOs showed subtype-specific differences in glycolysis and oxidative phosphorylation (OXPHOS). Basal-like tumor-derived PDOs had a lower baseline extracellular acidification rate, but higher glycolytic reserves and oxygen consumption rate (OCR) than classical tumor-derived PDOs. OCR difference was eliminated following treatment with UK-5099. In the 13C-glucose metabolites tracing experiment, a basal-like tumor PDO showed lower fractions of some M + 2 metabolites but higher sensitivity to UK-5099 mediated reduction in M + 2 metabolites than a classical tumor PDO. Protein level analyses revealed lower MPC1 protein levels in basal-like PDAC cases and association of low MPC1 levels with clinicopathologic parameters of tumor aggressiveness in PDAC. PDO differential gene expression analyses identified additional subtype-specific cellular pathways and potential disease outcome biomarkers. CONCLUSIONS: Our findings point to distinct metabolic profiles in PDAC subtypes with basal-like tumor PDOs showing higher OXPHOS and sensitivity to MPC1 inhibition. Subtypes-specific metabolic vulnerabilities may be exploited for selective therapeutic targeting.

The common, VTE-protective, G haplotype of F5 increases factor V-short, TFPI function, and risk of bleeding.

The G haplotype is a group of co-inherited single nucleotide variants in the F5 gene that reduce venous thromboembolism (VTE) risk. Even though seven percent of the population is homozygous for the G haplotype (F5-G/G), the underlying mechanism of VTE protection is poorly understood. Using RNA-seq data from 4,651 blood donors in the INTERVAL study we detected a rare excision event at the FV-short splice sites in 5% of F5-G/Gs as compared with 2.16% of homozygotes for the F5 reference sequence (F5-ref) (p=0.003). Highly elevated (~10-fold) FV-short, an FV isoform lacking most of the B-domain, has been linked with increased tissue factor inhibitor alpha (TFPIα) levels in rare hemorrhagic diathesis including East Texas Bleeding Disorder. To ascertain whether the enhanced FV-short splicing seen in F5-G/G INTERVAL participants translated to increased plasma FV-short levels we analyzed plasma samples from 7 F5-G/G and 13 F5-ref individuals in a recall-by-genotype study. A ~2.2-fold higher amount of FV-short was found in a plasma pool from F5-G/G participants as compared with F5-refs (p=0.029), but no difference in total FV levels. Whilst no significant difference in TFPI levels were found, F5-G/Gs showed a ~1.4-fold TFPI-dependent increase in lag time to thrombin generation compared to F5-refs (p=0.0085). Finally, in an analysis of 117,699 UK Biobank participants we discovered that, while being protective against VTE, the G haplotype also confers an increase in bleeding episodes (p=0.011). Our study provides evidence that the effect of the common G haplotype is mediated by the FV-short/TFPI pathway.

An action-observation method for studying social perception: a mini-review.

An important aspect of any social interaction involves inferring other people's mental states, intentions, and their likely next actions, by way of facial expression, body posture, eye gaze, and limb movements. An actor's production of actions during social interactions and the observer's perception of these actions are thus closely linked. In this review, we outline an action-observation methodology, which not only allows for separate analyses of production and perception, but also promotes the study of the dynamic interaction between these two sides of every social exchange. We review two lines of research that have benefited from its application. The first line focuses on individuals performing tasks alone and the observation of their actions by other individuals in order to make inferences about their attentional states. The second line of study focused on pairs of individuals performing collaborative tasks in naturalistic settings and the observation of these performances by other individuals. We offer several suggestions for how this methodology can be extended to improve on the limitations of the present studies, as well as some suggestions of how to use this methodology to venture into new territory. Our aim is to inspire future research applications of this methodology in order to advance our understanding of social action production and perception.

Tunable Elliptical Cylinders for Rotational Mechanical Studies of Single DNA Molecules.

The angular optical trap (AOT) is a powerful technique for measuring the DNA topology and rotational mechanics of fundamental biological processes. Realizing the full potential of the AOT requires rapid torsional control of these processes. However, existing AOT quartz cylinders are limited in their ability to meet the high rotation rate requirement while minimizing laser-induced photodamage. In this work, we present a novel trapping particle design to meet this challenge by creating small metamaterial elliptical cylinders with tunable trapping force and torque properties. The optical torque of these cylinders arises from their shape anisotropy, with their optical properties tuned via multilayered SiO 2 and Si 3 N 4 deposition. We demonstrate that these cylinders can be rotated at about 3 times the rate of quartz cylinders without slippage while enhancing the torque measurement resolution during DNA torsional elasticity studies. This approach opens new opportunities for previously inaccessible rotational studies of DNA processing.

An Effective Surface Passivation Assay for Single-Molecule Studies of Chromatin and Topoisomerase II.

For single-molecule studies requiring surface anchoring of biomolecules, a poorly passivated surface can result in alterations of biomolecule structure and function that can result in artifacts. This protocol describes surface passivation and sample chamber preparation for mechanical manipulation of chromatin fibers and characterization of topoisomerase II activity in physiological buffer conditions. The method employs enhanced surface hydrophobicity and purified blocking proteins to reduce non-specific surface adsorption. This method is accessible, cost-effective, and potentially widely applicable to other biomolecules. For a complete list of publications that employ this protocol, see the paper references. GRAPHICAL ABSTRACT: B.

Toward standardized brain tumor tissue processing protocols in neuro-oncology: a perspective for gliomas and beyond.

Implementation of standardized protocols in neurooncology during the surgical resection of brain tumors is needed to advance the clinical treatment paradigms that use tissue for diagnosis, prognosis, bio-banking, and treatment. Currently recommendations on intraoperative tissue procurement only exist for diffuse gliomas but management of other brain tumor subtypes can also benefit from these protocols. Fresh tissue from surgical resection can now be used for intraoperative diagnostics and functional precision medicine assays. A multidisciplinary neuro-oncology perspective is critical to develop the best avenues for practical standardization. This perspective from the multidisciplinary Oncology Tissue Advisory Board (OTAB) discusses current advances, future directions, and the imperative of adopting standardized protocols for diverse brain tumor entities. There is a growing need for consistent operating room practices to enhance patient care, streamline research efforts, and optimize outcomes.

Transoral Laser or Robotic Surgery Outcomes for Oropharyngeal Carcinoma: Secondary Analysis of the PATHOS Randomized Clinical Trial.

Background: Transoral robotic surgery (TORS) or transoral laser microsurgery (TLM) offer excellent oncological outcomes for oropharyngeal squamous cell carcinoma caused by human papillomavirus (HPV) infection. TORS may offer greater margin clearance around tumors than TLM. Objective: To determine whether the differing energy sources used and surgical technique of TORS or TLM is associated with postoperative early swallowing function, feeding tube use, and specific factors related to quality of life. Design, Setting, and Participants: This prespecified cohort study was performed within the Postoperative Adjuvant Treatment for HPV-Positive Tumours (PATHOS) randomized clinical trial at 40 centers in the UK, Germany, France, the US, and Australia between November 1, 2015, and August 31, 2023. PATHOS trial participants with HPV-positive oropharyngeal carcinoma of stages T1 to T3 and N0 to N2b M0 (TNM7) who underwent TLM or TORS were eligible. Of 989 consecutively recruited patients on the PATHOS trial, 508 were eligible for this substudy. Exposures: The exposure of interest was TORS or TLM. Main Outcomes and Measures: Preplanned outcome measures included nasogastric tube insertion rates within 4 weeks after surgery, length of in-hospital stay following surgery, specific scales from the MD Anderson Dysphagia Inventory (MDADI), 35-item European Organization for Research and Treatment of Cancer Head and Neck Questionnaire (H&N35), and 30-item Quality of Life Questionnaire (QLQ C30), water swallow test results, and videofluoroscopy scores. Results: Of the 508 patients included in the analysis (390 [76.8%] male; median age, 58.3 [IQR, 52.8-63.6] years), 195 had TLM and 313 had TORS. Nasogastric tube insertion rates were higher after TORS than TLM (85 of 189 [45.0%] vs 10 of 126 [7.9%]; adjusted odds ratio [OR], 4.41 [95% CI, 1.01-19.32]). Mean scores favored TLM with small effect sizes in all MDADI domains and the H&N35 swallowing item at 4 weeks after surgery; between-group difference for the MDADI composite score was -4.89 (95% CI, -8.27 to -1.50); for the MDADI physical functioning score, -6.37 (95% CI, -10.15 to -2.59); for the MDADI global score, -10.02 (95% CI, -16.50 to -3.54); and for H&N35 swallowing score, 7.24 (95% CI, 2.17-12.30). No other measures showed evidence of clinically meaningful differences. Conclusions and Relevance: In this cohort study, functional outcomes were moderately less impaired 4 weeks following TLM compared with TORS. Once the longer-term outcomes for these patients are known, these findings could aid the design and use of future head and neck-specific surgical robots. Trial Registration: ClinicalTrials.gov Identifier: NCT02215265.

Left Atrial Appendage Occlusion vs Standard of Care After Ischemic Stroke Despite Anticoagulation.

Importance: Patients with atrial fibrillation (AF) who have ischemic stroke despite taking oral anticoagulation therapy (OAT) have a very high risk of recurrence. Left atrial appendage occlusion (LAAO) is a mechanical stroke prevention strategy that may provide additional protection in patients with thromboembolic events under OAT. Objective: To compare percutaneous LAAO with continuing OAT alone regarding stroke prevention in patients with AF who had a thromboembolic event despite taking OAT. Design, Setting, and Participants: This cohort study was a propensity score-matched comparison of the STR-OAC LAAO cohort, an international collaboration of 21 sites combining patients from multiple prospective registries of patients who underwent LAAO between 2010 and 2022. STR-OAC LAAO cohort patients who had follow-up longer than 3 months were propensity score-matched to a previously published control cohort comprising patients from an established international collaboration of investigator-initiated prospective studies. This control cohort included patients with nonvalvular AF, recent ischemic stroke or transient ischemic attack, and follow-up longer than 3 months who were taking OAT before the index event. Analyses were adjusted for imbalances in gender, age, hypertension, diabetes, and CHA2 DS2-VASc score. Exposure: Left atrial appendage occlusion vs continuation of oral anticoagulation therapy alone (control group). Main Outcomes and Measures: The primary outcome was time to first ischemic stroke. Results: Four hundred thirty-three patients from the STR-OAC LAAO cohort (mean [SD] age, 72 [9] years; 171 [39%] females and 262 [61%] males; mean [SD] CHA2 DS2-VASc score, 5.0 [1.6]) were matched to 433 of 1140 patients (38%) from the control group. During 2-year follow-up, 50 patients experienced ischemic stroke: an annualized event rate of 2.8% per patient-year in the STR-OAC LAAO group vs 8.9% per patient-year in the control group. Left atrial appendage occlusion was associated with a lower risk of ischemic stroke (hazard ratio, 0.33; 95% CI, 0.19-0.58; P < .001) compared with the control group. After LAAO, OAT was discontinued in 290 patients (67%), and the remaining 143 patients (33%) continued OAT after LAAO as an adjunctive therapy. Conclusions and Relevance: In patients with nonvalvular AF and a prior thromboembolic event despite taking OAT, LAAO was associated with a lower risk of ischemic stroke compared with continued OAT alone. Randomized clinical trial data are needed to confirm that LAAO may be a promising treatment option for this population with a very high risk of stroke.

Glomus Tumor of the Chest Wall With Metastases to Lung.

Glomus tumors are typically benign, soft tissue neoplasms composed of thermoregulatory glomus bodies. The more common varieties, such as subungual, are treated surgically and typically have a very low mortality rate. Malignant glomus tumors are very rare, and their pathogenesis is poorly understood. As such, treatment options and prognosis are unclear. We present a 67-year-old female diagnosed with a chest wall glomus tumor with biopsy-proven metastases to her lungs. Her treatment course included neoadjuvant radiation therapy followed by immunotherapy with pembrolizumab. After completion of the initial radiation therapy, imaging showed disease regression. Interval imaging after seven months of immunotherapy showed the resolution of all lung nodules with no reported concerns for disease recurrence. Pembrolizumab was discontinued due to concerns for dermatologic and renal adverse events, and the patient continues to be monitored off therapy. The metastatic glomus tumor described in this case had several unique qualities, including its initial presentation on the chest wall as an aggressive lesion, as well as its spread to multiple locations in the lungs. Glomus tumors are not normally as aggressive as seen in this case, but the genetic profile with high tumor mutational burden allowed for guided treatment. Radiation is often used as neoadjuvant treatment in higher risk glomus tumors, but the addition of immunotherapy such as pembrolizumab represents a potential avenue to manage these patients when surgery is not an option. Malignant glomus tumors are exceptionally rare occurrences that, by nature of their rarity, require protocols or therapies that are not specifically designed for their treatment. The clinical course of these tumors is difficult to predict as most cases of metastatic spread have few examples from which to draw conclusions. This case provided encouraging results for treatment with radiation and, potentially, immunotherapy. Each instance of a malignant glomus tumor and its genetic profile should be closely examined and documented so that sufficient data can be accumulated to guide treatment for this rare cancer.

Brief Communication: Combination of an MIP3α-Antigen Fusion Therapeutic DNA Vaccine With Treatments of IFNα and 5-Aza-2'Deoxycytidine Enhances Activated Effector CD8+ T Cells Expressing CD11c in the B16F10 Melanoma Model.

Previous studies in the B16F10 mouse melanoma model have demonstrated that combining a DNA vaccine comprised of regions of gp100 and tyrosinase-related protein 2 fused to macrophage-inflammatory protein 3-alpha (MIP3α) with recombinant interferon alpha (IFN) and 5-Aza-2'-deoxycytidine (5Aza) treatments resulted in significantly greater antitumor activity and immunogenicity in the tumor microenvironment (TME). This brief report details that the combination of vaccine with treatments IFN and 5Aza results in an increase in the TME of a distinct CD11c+ CD8+ T-cell population. This cell population correlates with tumor size, is primarily comprised of effector or effector memory T cells, and has a more robust response to ex vivo stimulation as compared with CD11c- CD8+ T cells. In conclusion, this combination therapy results in a greater presence of highly active effector CD8+ T cells expressing CD11c in the TME, which are likely primary contributors to treatment efficacy.

Exploratory functional and quality of life outcomes with daily consumption of the ketone ester bis-octanoyl (R)-1,3-butanediol in healthy older adults: a randomized, parallel arm, double-blind, placebo-controlled study.

Background: Ketone bodies are metabolites produced during fasting or on a ketogenic diet that have pleiotropic effects on the inflammatory and metabolic aging pathways underpinning frailty in in vivo models. Ketone esters (KEs) are compounds that induce hyperketonemia without dietary changes and that may impact physical and cognitive function in young adults. The functional effects of KEs have not been studied in older adults. Objectives: Our long-term goal is to examine if KEs modulate aging biology mechanisms and clinical outcomes relevant to frailty in older adults. Here, we report the exploratory functional and quality-of-life outcome measures collected during a 12-week safety and tolerability study of KE (NCT05585762). Design: Randomized, placebo-controlled, double-blinded, parallel-group, pilot trial of 12-weeks of daily KE ingestion. Setting: The Clinical Research Unit at the Buck Institute for Research on Aging, California. Participants: Community-dwelling older adults (≥ 65 years), independent in activities of daily living, with no unstable acute medical conditions (n = 30). Intervention: Subjects were randomly allocated (1:1) to consume 25 g daily of either KE (bis-octanoyl (R)-1,3-butanediol) or a taste, appearance, and calorie-matched placebo (PLA) containing canola oil. Measurements: Longitudinal change in physical function, cognitive function and quality of life were assessed as exploratory outcomes in n = 23 completers (n = 11 PLA, n = 12 KE). A composite functional outcome to describe the vigor-frailty continuum was calculated. Heart rate and activity was measured throughout the study using digital wearables. Results: There were no statistically significant longitudinal differences between groups in exploratory functional, activity-based or quality of life outcomes. Conclusion: Daily ingestion of 25 g of KE did not affect exploratory functional or quality-of-life end points in this pilot cohort of healthy older adults. Future work will address these endpoints as primary and secondary outcomes in a larger trial of pre-frail older adults.

SLC39A8.p.(Ala391Thr) is associated with poorer cognitive ability: a cross-sectional study of schizophrenia and the general UK population.

The missense SNP NC_000004.12:g.102267552C>T (SLC39A8.p.(Ala391Thr), rs13107325) in SLC39A8, which encodes a zinc transporter, has been linked to schizophrenia and is the likely causal variant for one of the genome-wide association loci associated with the disorder. We tested whether the schizophrenia-risk allele at p.(Ala391Thr) was associated with schizophrenia-related phenotypes, including positive, negative, and disorganised symptoms, cognitive ability, educational attainment, and age of psychosis onset, within three schizophrenia cohorts (combined N=1,232) and, with equivalent phenotypes, in a sample of population controls (UK Biobank, N=355,069). We used regression analyses controlling for age, sex, and population stratification. Within the schizophrenia cohorts, after correction for multiple testing, p.(Ala391Thr) was not significantly associated with any schizophrenia-related phenotypes. In the unaffected participants from the UK Biobank, the schizophrenia-risk allele at p.(Ala391Thr) was associated with significantly poorer cognitive ability and fluid intelligence, a lower probability of obtaining GCSEs or a degree-level qualification, and fewer years in education. There was no association between p.(Ala391Thr) and self-reported psychotic experiences in this cohort. The schizophrenia-risk allele was associated with poorer cognitive ability, but not psychotic experiences, in a volunteer sample drawn from of the general population. To determine whether p.(Ala391Thr) is associated with cognitive phenotypes in people with schizophrenia, and to understand the role of p.(Ala391Thr) in the aetiology of cognitive impairment in schizophrenia, larger independent samples are required.

Evolution of evolvability in rapidly adapting populations.

Mutations can alter the short-term fitness of an organism, as well as the rates and benefits of future mutations. While numerous examples of these evolvability modifiers have been observed in rapidly adapting microbial populations, existing theory struggles to predict when they will be favoured by natural selection. Here we develop a mathematical framework for predicting the fates of genetic variants that modify the rates and benefits of future mutations in linked genomic regions. We derive analytical expressions showing how the fixation probabilities of these variants depend on the size of the population and the diversity of competing mutations. We find that competition between linked mutations can dramatically enhance selection for modifiers that increase the benefits of future mutations, even when they impose a strong direct cost on fitness. However, we also find that modest direct benefits can be sufficient to drive evolutionary dead ends to fixation. Our results suggest that subtle differences in evolvability could play an important role in shaping the long-term success of genetic variants in rapidly evolving microbial populations.

The effect of exam retakes on future exam performance in a large classroom setting.

Assessing student mastery is often done by using exams. Inevitably, some students will complete remediation, which may include exam retakes. This method provides students an additional opportunity to take an exam that assesses the same objectives as the original exam, while using different questions. Although this form of remediation increases exam scores, it is also possible that students who prepare for an exam retake adversely affect preparation for an upcoming exam. Therefore, the purpose of this study was to determine whether studying for and taking an exam retake affected preparation for the next exam. We hypothesized that students who completed an exam retake would have lower than expected scores on their next exam. This study utilized data collected over five semesters from 467 students enrolled in a 200-level introductory human physiology class; 159 students (34.0%) completed at least one exam retake. Students who retook an exam increased their original exam score by 6.1% (SD 13.9). These findings suggest that retaking an exam leads to better outcomes, which could be explained by students improving their study habits or test-taking skills, which would help them perform better on future exams.NEW & NOTEWORTHY Exam retakes provide students with an additional opportunity to demonstrate mastery of learning objectives. However, this preparation might adversely affect performance on subsequent exams. This study suggests that students who choose to prepare for and take an exam retake not only improve their original exam score but show a larger improvement on subsequent exam performance than those students who did not take an exam retake.

Taxonogenomic analysis of the Xanthomonas translucens complex leads to the descriptions of Xanthomonas cerealis sp. nov. and Xanthomonas graminis sp. nov.

The pathovar-based taxonomy of the Xanthomonas translucens group is very confusing due to an overlap of plant host ranges and level of host specificity. Here, whole-genome sequence-based parameters (digital DNA-DNA hybridization and blast-based average nucleotide identity), phylogenomic, biochemical and phenotypical data were used to taxonomically analyse the 11 known pathovars of the X. translucens complex. This polyphasic approach taxonomically assigned the 11 pathovars of X. translucens complex into three distinct species, two of which are new: X. translucens, X. cerealis sp. nov. and X. graminis sp. nov. X. translucens consists of three pathovars: pv. translucens (=pv. hordei), pv. pistaciae strain A ICMP 16316PT and pv. undulosa (=pv. secalis). X. cerealis sp. nov. encompasses the pv. cerealis strain LMG 679PT and pv. pistaciae strain B ICMP 16317PT with genome similarity of 92.7% (dDDH) and 99.0% (ANIb) suggesting taxonomically similar genotypes. The other new species, X. graminis sp. nov., consists of the remaining five designated pathovars (pv. graminis, pv. arrhenatheri, pv. poae, pv. phleipratensis and pv. phlei) with highly variable dDDH and ANIb values ranging from 74.5 to 93.0% and from 96.7 to 99.2%, respectively, an indication of a very divergent taxonomic group. Only strains of pvs. phlei and phleipratensis showed the highest genomic similarities of 93.0% (dDDH) and 99.2% (ANIb), suggesting synonymic pathovars as both infect the same plant hosts. The dDDH and ANI data were corroborated by phylogenomics clustering. The fatty acid contents were similar but the type strain of X. graminis sp. nov. exhibited 20% less C15 : 0 iso and 40% more C17 : 0 iso fatty acids than the other species. Based on phenotypic, biochemical and whole-genome sequence data, we propose two new species, Xanthomonas cerealis sp. nov. and Xanthomonas graminis sp. nov. with type strains LMG 679T (=NCPPB 1944T) and LMG 726T (=NCPPB 2700T), respectively.

Does Mechanism of Injury Affect Recovery After Sport-Related Concussion in Basketball? A Pilot Study.

BACKGROUND AND OBJECTIVES: Understanding sport-related concussion (SRC) mechanisms can aid in prevention and treatment. Concussions in basketball have received relatively less attention compared with collision sports. In a cohort of concussed high school basketball players, this pilot study sought to (1) describe the mechanisms of how concussions occur in basketball and (2) assess the relationship between mechanisms and acute symptomatology and recovery time. METHODS: A retrospective cohort, pilot study examined concussed adolescent athletes (aged 14-18 years) treated at a sports concussion center from 11/2017 to 04/2022. The primary independent variable was mechanism of injury, categorized into (1) contact (head-to-head, head-to-body, head-to-ball, head-to-ground), (2) player (offensive play, defensive play, both), and (3) awareness mechanisms (aware, unaware). The outcomes included acute symptom severity, time to return-to-learn, symptom resolution, and return-to-play. Associations between mechanisms and outcomes were analyzed using one-way analysis of variance, independent t-tests, multivariable linear regressions, and Cox regression. RESULTS: Of 105 basketball players (16.2 ± 1.4 years; 50.5% male), head-to-ground contact (n = 44/105; 41.9%) was most common. Taking-a-charge (n = 12/53; 22.6%) was the most frequent player mechanism, with similar rates for offensive (n = 24/53; 45.3%) and defensive (n = 23/53; 43.4%) plays. Most were aware of impending collision (n = 37/46; 80.4%). Head-to-body concussions were associated with higher initial symptoms severity scores when compared with head-to-head (ß = 0.33, P = .003) and head-to-ground (ß = 0.23, P = .050) contacts. Player and awareness mechanisms were not significant predictors of outcome measures. Only higher initial symptom scores were associated with a longer time to return-to-learn, symptom resolution, and return-to-play. CONCLUSION: In this pilot study of concussed high school basketball players, head-to-ground was the most common concussion mechanism, with similar rates during offensive and defensive plays. Although head-to-body contact increased acute symptoms, other mechanisms did not predict recovery time. Given the limited information on concussions in basketball, the preliminary results of this pilot study may help inform larger studies on basketball SRC mechanisms.